Cooler Master has a series of affordable chassis called the N series. They're supposed to cool well and are made for liquid cooling including 240 mm radiators, perhaps making them a good and affordable option for a powerful rig. We tested four N series models and compared them to 28 other chassis in the same price segment.
Slow computer got you down? Maybe a hardware upgrade should be in your cards, if so this guide to the Fundamentals of Upgrading a PC is an invaluable read. PCSTATS Tips