if the sprouts are little dimply things, you can just cut them off/out. if they've grown proper legs, or gone impressively green, its really time to rehome them. do not munch.
how are you storing your spuds? if they're on a countertop in daylight, or in a warm humid spot, they'll shoot or turn to mush really fast. if they're somewhere cool, dry, and dark (like a cool airy shady cupboard or root cellar) they should last a fair while.
maybe the ones you're buying have been around for a bit too long before you got them.