Customized costumes and props made by costumers who sell their work through sites like Etsy, ebay, and Instagram are the highest quality, the most expensive, and you sure as F aint getting it in three days. You can find a lot of second-handed costumes. Just keep in mind Inexpensive costumes are made cheaply in mass numbers, regardless of whether the site brands itself as a Halloween store, a costume store, fat thor costume or a Cosplay store.