Collecting and selling first day covers are a great pastime that many people enjoy. First day covers are envelopes or stamps that are cancelled on the same day that the stamp is first put on sale by the post office. Selling your first day cover can be a way to make some extra funds.
Contact a local stamp collector or stamp dealer. They will take a look at your first-day cover to give an evaluation on what it may be worth. Ensure that you will be speaking with a stamp dealer that is knowledgeable in the field.
Decide on a price for your first-day cover. Once you have allowed a stamp dealer to evaluate your first-day cover, you will need to set the price that you would be willng to accept for it. Private collectors would most likely pay a little bit more than a dealer would.
Contact local dealers and collectors to see if any have an interest in your first-day cover. You may want to purchase a copy of the "First Days" publication. This publication contains advertisements from first-day dealers who are actively looking for first-day covers. You can begin to call those listed to get a competitive pricing.