How to Sell Stamps
Except for the stamps that you bought at the post office, it is possible to sell stamps and covers in the same places you bought them.
That means, sell them back to dealers, or advertise them for sale in the philatelic press, or sell them to fellow collectors at meetings of your stamp club, have a dealer sell them for you at auction, or offer them yourself in an internet auction. At every stamp show, dealers are there to buy as well as to sell, though it is not a good idea to interrupt a dealer who is working with customers to try to sell yours. Wait for a quiet moment and then talk about your business with the dealer.
Unusual sales opportunities include using what are known as "circuit books," part of the services of some of the philatelic organizations, including the American Philatelic Society in the U. S. Circuit or sales books are small booklets not unlike the old supermarket trading stamps books, in which a collector mounts the stamps or covers for sale, and prices them, and then the organization circulates them to other collectors by mail. The recipient can choose what to buy, sends the money to the organization, and sends the booklets on to the next collector. Circuit books are an excellent way to sell low- and medium-priced stamps and covers.
Running a classified ad in a few stamp publications is an inexpensive way to sell, too. It's a good idea to try to discover the most appropriate market for your material ahead of time - matching what you have to the best potential buyers. For example, offering your collection of United Nations to a dealer who specializes in Great Britain will probably be a waste of time, although sometimes a dealer is willing to buy "outside" his or her field if the material is something that could be turned over quickly. Perhaps the dealer could sell it to another dealer at a future stamp show.
It will be to your advantage to arrange your material in very specific groupings, and then offer it separately for sale, rather than mixing various countries together and offering it as "worldwide." Sometimes it's better to break it up according to popular topical categories - a grouping of birds, or trains, rather than a country collection. Reading the ads in the marketplace is a good way to get an idea of what sells, and for how much, so you can price your material accordingly. Values listed in places like the Scott Catalogue are estimated retail prices - what you would have to spend to buy that particular stamp in very fine condition. It is not the price a dealer would pay you, and it is definitely not the buying price for material in less than good condition.
A few words about stamp value: Value depends on condition, on quantity available, and also market demand. These factors balance each other. For example, if there are only a few examples of a certain stamp, and everyone wants one, then condition will be less important. People will be so anxious to have it they won't mind flaws as much. But, if there are millions of mint copies still available, then no one is going to pay top dollar for your stamp or cover.
There may be lots of copies, and if they are not popular to collect, it doesn't matter if the stamps are perfect or flawed, no one wants them anyway! If there are lots of copies, and the stamps are popular, then the best copies will command the best prices, but less perfect copies still will have a market. This is all common sense.
There are "fashions" and trends in stamps as in other markets, and the stamps you can't sell today may have their turn at some future time, as circumstances change. But, remember that this is supposed to be a hobby, something to be indulged in for fun, not for future profit. Collect for fun and you will never be disappointed