Abstract
Quadruped robots occupy a unique position in the secondary market. Unlike consumer robots (which face continuous competitive pressure from model upgrades) or industrial cobots (which are evaluated as capital equipment with documented service lives), quadrupeds serve a heterogeneous market spanning consumer hobbyists, university research labs, enterprise inspection teams, and defence contractors. This study tracks resale price trajectories for the Unitree Go2 and Boston Dynamics Spot from 2023 to 2026, identifying the structural factors that determine value retention in each platform and the risks that secondary-market buyers face in each segment. The Unitree Go2 retains 65–78% of retail value at 12 months, stronger than any comparable consumer robot. Spot retains 65–80% of purchase price at 24 months in documented enterprise condition, consistent with capital equipment. Both platforms' used-market values are substantially supported by demand from buyers who cannot or choose not to acquire new units.
1. Introduction
The quadruped robot category did not have a meaningful secondary market in 2021. Boston Dynamics Spot existed but was sold under terms that complicated resale; Unitree's earlier A1 model had a small research following but limited consumer adoption. By 2024, the market had changed substantially: the Unitree Go2's commercial success created a cohort of early-adopter sellers, Spot's transition to more permissive commercial terms enabled resale, and the entry of other platforms (Xiaomi CyberDog 2, AgileX LIMO) expanded the category.
By 2026, quadruped robots are the fastest-growing used robot category by transaction volume in the UK, starting from a low base. Understanding how values behave in this category is important for both buyers — who need to understand their acquisition risk — and for sellers and institutions deciding when to rotate platforms.
This study uses listing price data and achieved sale price observations from the UK secondary market, supplemented by the Robot AutoTrader robot database entries for these platforms and the used robot dog buyers guide.
2. The Unitree Go2: Consumer Product with Research Demand Floor
2.1 Platform overview
The Unitree Go2 launched in the UK in late 2023 across three variants: Air (RRP approximately £1,100), Pro (approximately £2,100), and EDU (approximately £2,800). The Go2 is the commercially successful successor to the Unitree A1 and B1, and represents Unitree's transition from a research-focused company to a product company targeting both consumer and professional markets.
The Go2 Pro is the UK's most actively traded used quadruped, with a secondary market that emerged from mid-2024 as first-generation buyers transitioned. For the resale analysis in this study, the Go2 Pro is used as the reference variant due to transaction volume sufficient for price series construction.
2.2 Depreciation trajectory
Go2 Pro units (RRP £2,100) depreciate as follows:
6 months post-purchase: £1,700–£1,950 (81–93% of RRP). Very few units available at this age; sellers at this stage are primarily businesses that piloted and did not continue.
12 months post-purchase: £1,400–£1,800 (67–86% of RRP). The modal secondary market price point. Battery health is the primary condition differentiator at this age; units with documented battery health above 90% trade at the top of this range.
18–24 months post-purchase: £1,150–£1,500 (55–71% of RRP). The volume trading range. Actuator noise and joint condition become additional differentiating factors alongside battery health.
36+ months: £800–£1,100 (38–52% of RRP). Limited data; very few Go2 units have reached this age as of the study close.
For context, a robot vacuum in the same RRP range (e.g. Roborock S8 Pro Ultra at £1,099) trades at 57–65% of RRP at 12 months — measurably weaker retention than the Go2 Pro at the same age. The Go2 Air shows weaker retention than the Pro, settling around 63–72% at 12 months, consistent with its consumer product positioning.
2.3 Structural drivers of retention
Developer community demand: The Go2 Pro has a large and active development community, with ROS2 packages, Isaac Sim integration, custom locomotion controllers, and community tutorials all extending the platform's utility beyond Unitree's own software. A two-year-old Go2 Pro is functionally equivalent to a new unit for the majority of research and development applications, which sustains demand at the 18–24 month age point where consumer electronic equivalents face steeper price pressure.
Research institution demand: UK universities with robotics research programmes view the Go2 Pro as an accessible research platform. Institutional buyers are less price-sensitive than consumer buyers and have longer purchasing timelines that smooth secondary market demand.
Battery health specificity: Go2 battery health affects resale value more predictably than in consumer robots because the Go2's battery capacity directly determines field operation time, a critical variable for outdoor research and inspection applications. Buyers in this segment are more technically capable of measuring and interpreting battery health data, which makes the market more efficient: healthy-battery units command premium prices, degraded-battery units are discounted accurately.
2.4 Condition risk factors
The primary risk factors for Go2 used buyers, in order of frequency and severity:
Battery degradation (most common): Go2 Pro batteries degrade from 100% to approximately 80–85% capacity over 12 months of normal use. Units with less than 70% capacity show noticeably shortened field time and trade at significant discounts. Request a timed continuous locomotion test from the seller; a healthy pack should run 55–65 minutes continuously at normal trot speed.
Actuator wear (significant at 18+ months): The Go2's electric actuators accumulate wear through normal use, particularly in the hip and knee joints. Mild wear is normal; sharp grinding or irregular clicking sounds under load indicate actuator degradation that will worsen. Inspect by running the robot through all gait modes in an open area.
Fall damage (occasional): Quadrupeds fall. The Go2 is reasonably robust but leg assembly impacts at speed or from height can crack the hip and knee joint housings. Inspect all four leg assemblies visually.
Camera calibration drift (Pro and EDU): The stereo camera calibration on Go2 Pro units can drift after significant use or a hard impact. Request a navigation demonstration using the obstacle avoidance mode — erratic behaviour in known-clear environments indicates calibration issues.
Full inspection methodology is in the used robot dog buyers guide. Current UK pricing is tracked at the Unitree Go2 Pro resale page.
3. Boston Dynamics Spot: Capital Equipment in a Robot Body
3.1 Platform overview
Boston Dynamics Spot is a categorically different product from the Unitree Go2 in every relevant dimension. It is enterprise software and service as much as it is hardware. Its primary customers are oil and gas operators, utilities, construction companies, defence contractors, and large-scale facilities managers. The UK secondary market for Spot is thin but transactions do occur, typically when enterprise customers upgrade to newer hardware revisions or when pilots do not convert to full deployments.
The UK Spot purchase price varies by distributor and configuration; a base Spot unit with standard controller was approximately £65,000–£74,500 in 2024. Payloads and software packages are additional. The Spot Enterprise software licence (required for full capability) carries an annual subscription fee.
3.2 Depreciation trajectory
Data for Spot is sparser than Go2 due to lower secondary-market volume. Based on observed transactions and expert assessment:
12 months: 76–88% of purchase price (documented enterprise condition). The narrow distribution reflects that buyers of 12-month-old Spot units are typically enterprise buyers who understand the market and pay close to documented value.
24 months: 65–80% of purchase price (documented enterprise condition). The range widens at this age, reflecting variance in hardware revision (Spot has had iterative hardware updates) and in payload configuration.
36 months: 55–70% of purchase price. Payload compatibility with current Spot SDK versions becomes a relevant consideration at this age.
These retention rates are among the strongest of any robot category tracked. They reflect Spot's structural position: it is the only enterprise quadruped with a proven field track record, a global service network staffed by roboticists, and a software platform that has been continuously developed and expanded since 2018.
3.3 The software subscription complication
Spot's resale market is complicated by its software licence model in a way that the Go2 market is not. Full Spot capability requires an active Spot Enterprise or Spot SDK licence. Licence transfer terms for secondhand units are not standardised and require direct engagement with Boston Dynamics. Buyers who complete a Spot purchase without confirming licence transfer may find themselves with hardware that requires a new licence purchase to access full capabilities — an additional cost of several thousand pounds that is not reflected in the hardware price.
This is not a hypothetical risk; it is the most commonly reported complication in Spot secondary market transactions. The mitigation is unambiguous: confirm licence transfer terms with Boston Dynamics in writing before committing to purchase.
The second software complication is payload compatibility. Spot's payload ecosystem has evolved alongside the platform, and payloads from early production Spot units (2020–2021) are not always compatible with current SDK versions. A payload that was integral to the original buyer's application may not function on a resold unit without software updates or hardware revision.
3.4 Why Spot retains value so strongly
The strength of Spot's secondary market value retention reflects a market with very limited alternatives. As of September 2026, no competitor has deployed an enterprise quadruped with Spot's combination of outdoor robustness, payload versatility, software maturity, and field support infrastructure. ANYbotics ANYmal is the closest alternative and targets a similar enterprise customer profile, but has a smaller global installed base and less mature third-party integrations.
Enterprise buyers purchasing a used Spot are acquiring a platform with a known track record in the specific conditions they are deploying into. The risk-adjusted value of a documented, field-proven Spot unit is high precisely because alternatives carry more uncertainty. Until a competitor achieves comparable field validation, Spot's used-market premium relative to competing platforms will persist.
4. Comparative Analysis
4.1 Value retention compared
| Platform | 12-month retention | 24-month retention | Primary value driver |
|---|---|---|---|
| Unitree Go2 Air | 63–72% | 50–62% | Battery health, consumer demand |
| Unitree Go2 Pro | 67–86% | 55–71% | Developer community, battery health |
| Boston Dynamics Spot | 76–88% | 65–80% | Enterprise position, service network |
4.2 Market structure difference
The Go2 and Spot secondary markets have fundamentally different structures. The Go2 market is liquid, price-transparent, and driven by consumer and research buyer behaviour familiar from other secondary electronics markets. Prices are discoverable through multiple platforms; transactions are relatively quick; and buyers have access to community-developed inspection knowledge.
The Spot market is thin, relationship-dependent, and driven by enterprise procurement processes. Transactions are slower, prices are less transparent, and the software licence complication creates friction that does not exist in consumer quadruped transactions. Buyers with enterprise procurement experience navigate this more naturally than those approaching the Spot market from a consumer-market background.
4.3 Which to buy used
Buy Go2 if: You have a defined research or development application, a technical background sufficient to evaluate battery and actuator condition, and a budget between £1,200 and £2,000. The Go2 Pro at 18–24 months old is the best-value entry point: meaningful depreciation has occurred, the developer ecosystem is mature, and battery health is assessable.
Buy Spot if: You have a specific enterprise application where Spot's field-proven outdoor capability, payload ecosystem, or enterprise support contract is necessary, and the budget to pay enterprise prices for enterprise equipment. Do not buy a used Spot as a consumer quadruped or a casual research platform — the economics do not work at the price point, and the software complexity will frustrate non-enterprise buyers.
The gap in the market: There is currently no used quadruped in the UK that bridges the Go2-Spot value gap effectively. Unitree's B2 (enterprise quadruped, approximately £25,000–£30,000 new) is beginning to appear on the secondary market but transaction volume is too thin for resale analysis. This gap is likely to fill over 2027–2028 as B2 and comparable platforms cycle through enterprise pilots.
5. Outlook
Unitree Go2 secondary market prices will face moderate downward pressure over 2026–2027 as Go2 supply increases (Unitree shipped approximately 5,900 humanoids in H1 2026, a figure that excludes Go2 volume, which remains their highest-selling platform) and as Unitree's next-generation quadruped releases create some demand substitution. Go2 Pro prices are expected to settle in the £1,100–£1,500 range at 18–24 months by mid-2027, reflecting a slight widening of the current discount.
Spot secondary market prices are expected to remain stable through 2026–2027 absent a major competitive entrant in the enterprise quadruped segment. Boston Dynamics' continued software development sustains the platform's capability value, and the absence of a credible alternative at equivalent field-validation levels provides structural price support.
Current UK quadruped listings are in the browse section. Related research on humanoid platforms and the broader robot secondary market is available in the research section.
Working paper. Data current to September 2026. UK secondary market observation basis. Not peer reviewed. Go2 Pro is the reference variant for all Go2 analysis; Air and EDU show different trajectories as noted.