It all depends where you live. I suggest if I were you, go online to Google and type (with the quotation marks, include them) "cheap prom dresses" and since google knows where you are it will tell you.
For changes,you can buy it online.
You can get really cute purple dresses at Kohls! I was shopping at Kohls the other day and i saw a really cute purple one with black lace at the top.
Wal-Mart has a cute line of dresses that are cheap and great for the summer. You can also find shoes that match the outfit in the next department over.
for a floral dress go to:forever21charlotte roussejcpenneymacy'sfor accesories for sure go to forlove in the mall
You can find really cute prom dresses at: JC Penny Dillard's and there could be more stores.
I got really cute tankini from boden and it is in all sizes and it is just soo super nice!
Debs
wal-mart
Primark is one place: they are cheap and cheerful!
The thrift shop.
Thrift stores are a great place to find a cheap prom dress, however, just keep in mind that the dress will be used and only in limited sizes. Plus, the style may be outdated.
you can probably find one
You could find a cheap prom dress at a Consignment Store or a Resale Store. You could also check out thrift stores. All these stores have inexpensive clothing.