Give them to me (or at least all of your bugs, pyros and dinosaurs)! = D But ebay hoặc any other auction website is a good option. If bạn have a swap meet hoặc something locally, bạn can also sell them there. hoặc bạn could donate them to Goodwill hoặc any other charity organization.
Since they ARE collector's cards, though, I'd keep and display them. Use them. Maybe start a trading service.