PCPartPicker part list:
http://pcpartpicker.com/p/Jrys
Price breakdown by merchant: http://pcpartpicker.com/p/Jrys/by_merchant/
Benchmarks: http://pcpartpicker.com/p/Jrys/benchmarks/
CPU: AMD Phenom II X4 965 Black 3.4GHz Quad-Core Processor ($97.99 @ NCIX US)
Motherboard: ASRock 970DE3/U3S3 ATX AM3+ Motherboard ($69.99 @ Amazon)
Memory: Kingston Black 8GB (2 x 4GB) DDR3-1600 Memory ($58.99 @ NCIX US)
Storage: Seagate Barracuda 500GB 3.5" 7200RPM Internal Hard Drive ($58.98 @ Outlet PC)
Video Card: Sapphire Radeon HD 7850 1GB Video Card ($154.99 @ Newegg)
Case: Zalman Z5 ATX Mid Tower Case ($24.99 @ Newegg)
Power Supply: XFX 550W 80 PLUS Bronze Certified ATX12V / EPS12V Power Supply ($59.99 @ Newegg)
Optical Drive: LG GH22NS90B DVD/CD Writer
Operating System: Microsoft Windows 7 Home Premium SP1 (OEM) (64-bit) ($89.98 @ Outlet PC)
Total: $615.90
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-03-13 12:42 EDT-0400)
this is what i have gathered as a decent build so far.. and 8 and 7 are the same price, at least where i'm looking.