Things You'll Need
Instructions
Find the Value of a Stamp
Check auction sites such as eBay or Stamporama for previous sales of your stamp. The value of a stamp is what the market is willing to pay for that stamp, and if someone has sold a stamp identical or similar to yours recently then you can get a good idea of what your stamp is worth.
Ask around on an online stamp collecting forum, such as Stamporama. Other collectors may have knowledge of your stamp and may be able to give you an estimate of what the stamp is worth. And even if they aren't able to tell you what the stamp is worth they may be able to tell you things about the stamp you didn't know, which can be useful for determining value.
Check the phone book or Google Maps for stamp collectors or antique collectors in your area. They may also have information on what the stamp is worth. Some more established stamp collectors will also have records of previous auctions, which can be a great resource for finding previous auction sales of your stamp or stamps like it.
Consider putting your stamp up for auction on eBay or another auction website with an extremely high reserve price. In all likelihood, the stamp won't be sold and you will get to see what the top bid is. Know, however, that there's always the chance that someone will meet your reserve price. You should only do this if you're willing to sell your stamp.