If you’re like me, then you grew up collecting and trading baseball cards: Trying to assemble your favorite players, placing them in plastic sleeves and, ultimately, forgetting about them. Then, twenty years later while cleaning out your attic or garage, you find that dusty box full of your forgotten collection. As you sort through the cards, the thought crosses your mind: How much are these worth today? Maybe in that box is an extra-rare card representing a big payday. You may indeed sell your cards for a nice profit, but don’t forget: this profit is taxable under the Collectible Gains Tax.