Evey -
You probably already know this but, do you have a JoAnn's Fabrics near you? If not, you can find them online (joann.com) & they've sometimes got great clearance items. So does A.C. Moore Arts & Crafts (acmoore.com). Also, I've given away free, leftover arts & crafts on freecycle.com & craigslist.org, so perhaps searching your local chapters may help. I also belong to several free yahoo groups that are along the lines of freecycle, as I periodically have items to give away. Perhaps you can find a few in your area.
Good luck. What is your Halloween costume, by the way? Unless you can't tell us as it's a spooky, scary secret you'll spring on us in Oct... VV