where can i buy a formal dress?

im going to pv in about a month and was hoping i could find an inexpensive dress to wear to my prom. i want something that i know will be different from everyone elses and i figured buying a dress in a totally different country would take care of that right. does anybody know of any stores where i might be able to find a dress? i was kind of hoping for a salsa style dress . any suggestions?
thanks!

at the shopping area by Gigante is a Lans and then downtown is an LOB... just head downtown and start walking the streets there are a lot of stores that have some really nice clothes for you to sample.....

alright thanks. i will definately check out both stores. ive been to LOB before and actually bought a few clothes there the last two years i was in PV. i love their clothes!