Asking prices are not sale prices
Online listings show what sellers hope to receive, not necessarily what buyers paid. Use recent completed transactions from credible sources where available, compare the same reference and condition, and account for regional differences and currency conversion.
Condition and configuration matter
Originality, size, material, colour, condition, completeness, service history and documented provenance can all affect buyer interest. Some popular items still need discounting to sell; other unusual pieces may have very few buyers.
Calculate the cost to exit
A resale estimate should deduct platform commission, authentication, cleaning or service, shipping, insurance, currency exchange and applicable taxes. The resulting amount may be materially lower than the headline comparison with retail price.
Buy for use, not a forecast
Luxury markets change with design cycles, supply, brand policy and consumer taste. No maker, model or scarcity story guarantees a gain. If affordability depends on future appreciation, the purchase is too risky; buy only when the object itself is worth owning to you.