Don't wait until October to look for costumes at thrift stores: the best time is NOW! I visited our local Salvation Army yesterday, and noticed that they had two racks fully stocked and ready to go (that's my son in the photo below). By mid-October, they're likely to be picked over. Don't just look for halloween costumes, also look for fun hats, wigs, accessories and other items to throw in your child's dress-up bin. For items that can't be laundered, consider spraying them with a disinfectant spray like Lysol before using them.
Want to get creative with your costumes? Visit the Mommysavers Costume Idea page for inspiration