Another idea about looking for that bargain prom dress. Look for your local Outlet Mall and go to the designer department store outlets. For example: Nordstrom's has one and then there's Saks Fifth Off. They have lovely formal clothes.
Also check out the sale racks of bridal stores. They have lots of bridesmaid dresses you could put to good use. My friend got her dress and the other dresses for her party at a bargain bridal store, they were lovely.
By Pamphyila from Los Angeles