I've found it's cheaper to just buy them at a retail store. The shipping on cases sucks pretty badly, and cases are one of the few parts that ends up being about the same price when you compare say Fry's with Newegg.
By the way, check and see if you have a CompUSA closing near you. I got my case for 30% of the list price (which was the same as Newegg for once) and I avoided shipping costs.