- 1). Have your stamps appraised. The American Philatelic Foundation, a non-profit organization, has an appraisal service that determines the prices of stamps. Stamp dealers also perform appraisals.
- 2). Look at price guides. Scott Publishing Company publishes annual guides with prices of United States, United Nations and international stamps. The House of Collectibles publishes "The Official Blackbook Price Guide to United States Postage Stamps."
- 3). Check out the market value of stamps. Sometimes, there is a difference between a stamp's list price and a dealer's asking price. The dealer may think that a stamp is undervalued and offers it for more money. Or, the public can think a stamp is overvalued and customers won't pay book price, thus driving the price down. A publication such as "Linn's Stamp News" has advertisements from dealers and auction houses.