Some families like to make their costumes from "found" items. In other words, they like to participate but don't like the hefty price tag of buying pre-made costumes. The bins in my shed have been raided many times for costume pieces. I have random parts and pieces that can be used in various ways to create different "looks." And, believe me, my kids and even some neighbors have come up with interesting characters from my random costume pieces.
One year, my sister was looking to make a Harry Potter costume for her boy and needed a cape. She asked me for help making one. I said, "Capes are so easy. Just go to the thrift store and find a black woman's skirt. Take apart one seam, and add a black ribbon tie. Voila' - a cape." It was a revelation to her.
Yup. When you have to make a lot of costumes without a commensurate budget, you learn to be creative!
Happy hunting for costumes!