Dell N230P-00 - 230W ATX Power Supply for Dell Optiplex 210L 320 330 360 GX520 Dimension E310 3100 5150 Desktop Computers - CPU Medics
Refurbished: Dell Optiplex GX520 Small Form Factor - 2.5GHz Intel Celeron Processor - 2GB Memory - Windows 7 Home Premium (1 Year Warranty) - Newegg.com
Dell N220P-01 - 220W Power Supply for OptiPlex GX520 GX620 SFF XPS 200 Dimension 5100C 5150C - CPU Medics
Best Buy: Dell Optiplex Desktop Computer 2 GB Memory 40 GB Hard Drive GX520