A comp is a chosen comparison
A comparable sale is a recorded sale you have checked against your target. A search result becomes useful only after you confirm what actually sold.
An asking price shows what a seller wants. A market estimate is calculated by a service. Neither is automatically a recorded sale of the exact item you are researching.
Match before doing the maths
- Exact itemMatch name, set, full number, language and version, or the exact sealed product and edition.
- Sale unitSeparate one card from a bundle, lot, pack or case. Do not compare a whole lot's price with one card.
- Raw or gradedKeep raw sales separate from graded sales. For graded comparisons, match the grading company and grade as well as the card.
- Condition and sale contextCheck supplied condition information and relevant sale details. If the evidence does not support a comparison, record the uncertainty rather than pretending it matches.
- Date and costsUse a suitable date range and the same currency. Know whether shipping is included before comparing totals.
Practice example — made-up prices
Suppose three confirmed one-card sales match the target's printing and supplied condition description. Their delivered totals in the same currency are $28, $30 and $32. The middle result is $30, and the observed range is $28–$32.
A $90 listing is still an asking price if it has not sold. A $100 sale for a different graded version is not a fourth raw-card comp. A $20 sale of the wrong language does not become relevant just because it is cheaper.
The three suitable sales provide evidence for a comparison; they do not guarantee a buyer or seller will agree to $30 today.
Check the recorded amount
When a Best Offer was accepted, the original listing price may differ from the accepted amount. eBay Product Research can show recorded accepted Best Offer prices. Use an amount that your source actually reports; do not silently treat the original ask as the final price.
A sale result can also have incomplete context. Keep a short note of the source, date, identity, amount and any exclusions so you can explain how you reached your view.
When results are sparse or inconsistent
Say how many useful matches you found. Broaden the time period carefully and label older evidence. Look for a reason behind an unusually high or low result before including or excluding it.
If the closest results still differ in important ways, say that the comparison is weak. Averaging more mismatched results does not fix the underlying identity problem.
Common mistake
Picking the highest sale because you own the card, or the lowest because you want to buy it. Apply the same matching rules in both directions.