House of Humor sells Halloween costumes, masks, wigs, whatever you need for a magic show or a party, you can kind if here.
I personally have found this store to reek. It's smelly, because of all the, polyester, or I don't know. But they sure have a lot of costumes.
I actually come here a lot, espeically for spirit week at my little brother's school and he needs a blue wig fast or something.