You can sell them on the steam market? I think they go for 12 cents a card. I made a 3 dollar profit once enough to buy DLC for a game.. It's not much but it's the most you're going to get, unless you've got a foil card.

I don't know but I sold all my card easily on the steam market

Did you check here yet? That's one place I've looked, but you will probably get a better answer from traders...

true the other option if you don't care is give them to your friends. You would have to socialize with them to do it, but that is life.

http://steamcardexchange.net/index.php

Not a site that will assess your collection in bulk, but it does have a nice, easy to access list of market values. At least it's easier than actually browsing the marketplace itself. There are also bots out there somewhere that will give you (admittedly low) Ref/Key values for your cards, if you're into TF2 items.

EDIT: Right, links are dumb here, I forgot. >,<