Since the other one was deleted i'll re-reply (haha)
Dicks and Sports Authority both sell pre-packaged corkies for about a buck a package, the number in the pack depends on the size of the corkies. Yarn can also be purchased from both for about a buck and a half to 2 bucks a package, however for yarn i prefer going to bi-mart for store bought stuff. They have a larger selection. Bi-mart also lets you pick your own corkies and put them into a bag, 6 for a buck.