Where to find cute summer dresses?

for 8th grade graduation all my friends that already have a dress are prom dresses. i think its funny how its only 8th grade graduation and they are spending up to 400 dollars on a dress. and they look like they should be going to prom, not a graduation from middle school. so i wanna be a little diffrent. im looking for a summer dress instead. i was wondering if anyone knew of cute summer dresses that are a tinny bit formaler and are stunning! thanks:)