Things You'll Need
Instructions
Know that the oldest and most respected reference guide for pricing football cards is "Beckett's Football Guide." "Topps Price Guide" is also a good reference, but Beckett's is the collector’s standard. You can pick either up at most any bookstore, or order one directly from their web sites. If you can afford it, buy both--so you can crosscheck prices.
Go through the price guide and find each of your cards and the corresponding prices, taking thorough notes as you go. As you’ll notice, there will be different prices listed for each individual card, depending on its current physical condition. In the case of most cards, the condition is obvious. Cards that are new or barely handled are usually considered “mint” (MNT) or near mint (NRMT), while worn cards with easily visible bends and smashed edges are considered “poor” (P). The hard part comes when determining the condition of those cards that fall somewhere in the middle of two classifications.
Consider that the difference between a mint condition card, a near-mint condition card and an “excellent-mint” (EX-MT) one can be very slight--perhaps no more than a slightly soft corner or tiny crack. To avoid any bad judgments on your part, take the cards you are not sure about to a few local card shops and ask the experts there what they think these particular cards are worth. Tell them what quality level you believe each card represents, and have them explain to you why you are mistaken. While in these shops, make sure to compare your estimated prices with comparable cards at each location.
Take some time to price some cards up for bids at auction sites like eBay. Internet sales have changed the pricing of many older less-than-mint cards and some rarities. You may have a few that are not priced at much, but have sentimental value to someone.