The value of the cards in my collection is the enjoyment I receive from them. One of my favorites is a baseball card that I paid less than $1.00 for. It depicts a scene from one of my most favorite moments in a post season game. But cards do have monetary value. The most famous of the "big money" cards is the Honus T. Wagner card which was printed by the American Tobacco Company in 1909 as part of the T206 White Border Set. The card is so valuable today not because of Mr. Wagner's baseball skills, but because this card was short printed making it the hardest to come by card in the set. And so it is not just the popularity of a player that commands a card price, it is scarcity. A Mickey Mantle rookie card in great condition can command a price not only because Mickey was such a great player, but because not all of those cards printed survived intact. There was a time when a popular activity among children was to put baseball cards in the spokes of their bikes and enjoy the rat a tat sound they made.Cards for keeping were rubber banded and thrown in cigar boxes. But you are here to learn to sell baseball cards and so what you really want to know is "At what price are my cards selling for at the time I want to sell them?"

The first thing you will need is a price guide to help you identify the year, manufacturer and set your card belongs to. The price guide will also give information about determining the condition of your card, error cards and card variations. The prices in these guides will give you an idea of what the card may sell for, but only an idea. Prices of newer cards can fluctuate as a player becomes more or less popular. Prices for older cards do not fluctuate as much unless an event occurs, such as a Hall of Fame induction.In price guides you are usually given a high and low price. Cards that are sold at card shows and on eBay usually sell at 1/2 half or less of high book prices unless they are "hot" cards in high demand at the moment or cards that are very scarce.
Once you have identified your card and have an idea of its condition it is time to see if there is a demand for it. Suppose you have a 1982 Topps Cal Ripken rookie card. Go to eBay and type in the search bar "1982 Topps Cal Ripken rookie". When the list of cards for auction comes up, pay it no mind. Instead, look on the left and scroll down a little to find a section called "Search Options". Check the little box marked "Completed" then click the "Show Items" button which will take you to pages of completed listings that will show you ending prices of recent auctions for that card.
So your next step is to ask "Where Can I sell my cards?"

Local card shows
If you have more than a few cards to sell and have done your research to determine if the cards you have are in demand, you might want to sell at a local card show that you find in the classifieds of your newspaper or weekly advertiser or by searching
for shows in your area at the Beckett Show Calendar
You will have to spend some money to participate. Table space could be as low as $10 or even $50 or more depending on the size and popularity of the show. In many states you will need a vendor's license. Call your County Auditor's office for this information.
Selling on eBay
Feedback is everything on eBay! If you have zero, or very little feedback, customers will pass you by and head for someone who looks more trustworthy. Start out selling on eBay by buying and selling low priced items to build up your feedback rating. Listing on eBay is not free. You will pay an insertion fee to list your item and another when your item sells. Why do people pay to list on eBay? Because eBay brings TRAFFIC to your listings.Here is an eBay page that will tell you how to get a seller account, list an item, calculate fees etc. Selling

If you feel you don't have the time or inclination to sell on eBay you might want to find an eBay trading assistant to sell items for you.Click here
to find a trading assistant near you.
Amazon
You can list sports cards for sale on Amazon. I have never done this so I can not say if cards sell well on there. There is no fee to list a card but there is a transaction fee as well a a percentage fee if your card sells.You can read about Amazon's selling policies here Sell Your Stuff
NAXCOM
This is another site that I have no experience selling on. There is no fee to list a card but you will be charged a fee if your item sells.Naxcom