Gas prices and interest rates are up and the stock market and home values are down. No wonder the thought of plunking down $39.50 for that Disney Tinker Bell Halloween costume is making you feel a little queasy. We've got the answer: go old-school with our easy make-it-yourself costumes. We've got 10 "one buy" ensembles -- costumes that will probably only require you to purchase one item. Chances are you've got the rest of the materials hanging around your house.