I have the best dress for our spring formal, and it was only $45! I can't find a picture online, but it's strapless, corally pink with gold flecks, and a slightly flouncy skirt. It was $30 but I had to buy it two sizes too big and then have it altered - but so worth it!
I also got a great dress for Pref - I'd had an old black one from a TWIRP dance, but it looked like too many others, and I have one from formal this fall, but that was too formal. I'd resigned myself to wearing one of those, but then I was at the Limited with my mom and saw this black strapless dress that is just below knee-length and has criss-crossing sequins - it was $70 and we got it for $40 after our coupons!
I love dress shopping, I always get awesome deals!