Compare exact catalog identity and condition rather than the same portrait or color.
Identification rule: record what is visible before assigning a catalog number or value.
What to record
- Catalog number and recognized variety.
- Mint or used status and gum condition.
- Centering, faults, certificate, and grade.
- Date and venue of completed sale.
What commonly causes mistakes
- Asking prices can be arbitrary.
- Common modern stamps are often mislabeled rare.
- A certificate for a different stamp proves nothing.
A practical research sequence
- Build a narrow comparison set.
- Exclude damaged or uncertified examples when inappropriate.
- Normalize buyer premium and shipping.
- Use ranges, not one dramatic result.
Condition and value
Value depends on exact identity, condition, centering, gum or cancellation, faults, certification, demand, and a defensible comparison set. A famous design does not automatically make an individual example rare.
Compare current collector listings
Use listings to study descriptions, scans, certificates, and market supply. Asking prices are not completed-sale evidence.
Compare collector listings