I recently built a new a pc. It's hard to find a nice looking case that doesn't cost much. I found a case for under $30 that looks decent. It's made by Powmax and comes in different colors. With some more fans and a better power supply it makes a nice case. Heres a pic...
I'm not trying to advertise or anything... You should check out NewEgg They have some pretty good prices. And a great selection.