I hear this question a lot. Mine is worth a lot, but then again, I count my collection as everything in the store, too. Technically it is mine until I sell it to you, or at least that’s what my insurance company tells me when they collect that giant premium every month. But yours? I have no idea. At least, not without it in front of me and a lot of time. I never give estimations of worth over the phone sight unseen.
There are a lot of factors that go into the value of a card. First, of course, is the player. Clearly there are players who are worth more than others. Then you have to consider the year. As players get better, they get more cards. So the early years are going to be worth more. Generally, the older the card the more it is worth, with rookie year cards worth the most. Next, we have to take into consideration how many identical cards are out there. In the boom years of the 80s/90s, they made so many cards that you can still buy pallets full of unopened packages. If there are still a lot of that particular card around, the valuation will be lower. The easier I can get the exact same card, the less I’ll be willing to pay top dollar for yours. After that is the condition, what kind of shape it is in. Is it graded or ungraded, and if it is graded, by which company? How much better is it than the other identical cards floating around out there? The better the condition, the more it will be worth. But here is the thing people have trouble understanding: the value of the card actually means nothing. It isn’t like money where the amount printed on it is the amount that you get out of it. You may have a card worth 50 grand, but unless I can line up a buyer for you when you want to sell it, the card’s value is zero. That is the difficult thing about any collectible item—you aren’t only dealing with the value of the item itself, you have to look at the other end as well: how much can I actually get for it? Your mint condition Mark McGuire rookie card might be worth a pretty penny, but blacklisted players like him, Canseco, Clemens, and Sosa can be super hard to offload.
Unfortunately, even knowing the above criteria does not mean I know the value of every card from every brand off the top of my head. The ones I am always looking out for or that I know will sell, I can absolutely give you a good idea of the ballpark price. However, there are just too many of them out there for me to be able to tell you with any confidence what every card is worth. That’s why I rely on things like the Beckett Guide to fill in the gaps in my knowledge. Here at the shop, it is used so often we just call it the bible.
Basically, what I am trying to say is that I’m not going to give estimated values over the internet or the phone. If that is what you’re looking for, I highly suggest visiting a local memorabilia shop or show to have someone who can physically look at your collection appraise it. They’ll be able to do it correctly and fairly, and you may be pleasantly surprised.