An expensive item may have a very thin market
Some collectible items show high asking prices but very few actual transactions. In these cases, theoretical price and liquidity must be treated separately.
A seller may wait months for a buyer who values a particular configuration or provenance. A quick sale may require a different range.
Observe sale frequency, listing duration and the difference between asking prices and completed transactions where data exists.
The thinner the market, the less credible an exact single-number valuation becomes.