ASUS P5NSLI LGA 775 NVIDIA nForce 570 SLI Intel Edition ATX Intel Motherboard - Retail
http://www.newegg.com/product/product.asp?item=N82E16813131032
$92.99
Rosewill RP550V2-D-SL 550W SLI Ready ATX12V v2.01 Power Supply - Retail
http://www.newegg.com/product/product.asp?item=N82E16817182030
$69.99
Intel Core 2 Duo E6400 Conroe 2.13GHz LGA 775 Processor Model BX80557E6400 - Retail
http://www.newegg.com/product/product.asp?item=N82E16819115004
$205.00
G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model F2-6400PHU2-2GBHZ - Retail
http://www.newegg.com/product/product.asp?item=N82E16820231065
$169.99
Total: $497.97
The best bang for the buck I could find in 2 hours.
http://www.newegg.com/product/product.asp?item=N82E16813131032
$92.99
Rosewill RP550V2-D-SL 550W SLI Ready ATX12V v2.01 Power Supply - Retail
http://www.newegg.com/product/product.asp?item=N82E16817182030
$69.99
Intel Core 2 Duo E6400 Conroe 2.13GHz LGA 775 Processor Model BX80557E6400 - Retail
http://www.newegg.com/product/product.asp?item=N82E16819115004
$205.00
G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model F2-6400PHU2-2GBHZ - Retail
http://www.newegg.com/product/product.asp?item=N82E16820231065
$169.99
Total: $497.97
The best bang for the buck I could find in 2 hours.