Is eBay an option?
If so check "Home > All Categories > Computers > Desktop PCs" for several options in the 2ghz range. They have several name brand new machines in the $500 range, and clones as low as $250~$300....which would be good for you since you'll be unemployed soon.
Personally, as cliche as it may be, I'd get a Dell. The advantage in that is that you know it will work because all the hardware was designed/chosen for that machine, and they have good support.