I used to order the parts separately directly from the importers and just build a PC from scratch. My desktop PC is still a custom built PC running Linux to avoid licencing costs of windows. As long as you have a decent amount of RAM, most modern hardware, even in the low-end range should do just fine for dev.
I used to DEV on an overclocked Pentium MMX 166MHz (overclocked to 200MHz) with 32MB of RAM while the rest of the world were bragging with their 1.5GHz PCs with many times more RAM than I had. Compiling in Delphi took an hour, so my code had to be perfect first shot, but that didn't stop me from DEVing. So you can make almost any hardware work for you, even a Raspberry PI can work fine for a DEV machine if you really need to stretch the budget.