How the numbers work
Methodology
An estimate is a summary of past auction sales joined to one catalog ID. It is not an appraisal, and it is not an offer. If a sale does not qualify, it stays out. If nothing qualifies, there is no number.
Where the sales come from
- Lots are auction sales we have joined to that catalog ID. That includes hammer prices and Buy It Now prices on auction sites, including eBay.
- Retail shopping prices are not included. We do not have sold prices from online dealers.
- A house name on an item page is a house present in that item's joined sales. We do not paste a logo wall.
- Population and variant counts appear only when we have them. We do not invent a census.
How the estimate is calculated
- The headline is the average of comparable single-copy sales, in US dollars. A sale in another currency with no USD amount is left out.
- Group lots are excluded. We do not divide a lot price by the number of copies.
- Premium variants stay out of the common average when we can tell them apart, so a scarce printing does not set the price of the ordinary one.
- When enough of those sales carry a grade, the average prefers grades near the middle of that set.
- The range is the middle half of that same set: the 25th to the 75th percentile.
- A scarce item with too few ordinary comps may use the thin set. The page says when it did that.
Free shows that estimate and five recent sales. Hammer opens five years of the same tape. Ledger opens the full joined record, including population and variant detail when we have it. Depth is the only difference. See pricing.
What we will not fill in
A wrong join is worse than a blank. Records can have typos, and a house can change a listing. Check the original auction page when the number matters. Questions about a record: contact us.