PCPartPicker part list:
http://pcpartpicker.com/p/NlZh
Price breakdown by merchant: http://pcpartpicker.com/p/NlZh/by_merchant/
Benchmarks: http://pcpartpicker.com/p/NlZh/benchmarks/
CPU: AMD FX-4130 3.8GHz Quad-Core Processor ($99.99 @ Newegg)
Motherboard: ASRock 970 Extreme3 ATX AM3+ Motherboard ($84.99 @ Amazon)
Memory: Crucial Ballistix sport 4GB (2 x 2GB) DDR3-1600 Memory ($26.85 @ NCIX US)
Storage: Western Digital Caviar Blue 500GB 3.5" 7200RPM Internal Hard Drive ($39.99 @ Microcenter)
Video Card: Sapphire Radeon HD 7790 1GB Video Card ($149.99 @ Newegg)
Case: NZXT Gamma Classic (Black) ATX Mid Tower Case ($39.98 @ Amazon)
Power Supply: Antec 450W ATX12V Power Supply ($37.80 @ Amazon)
Optical Drive: Lite-On iHAS124-04 DVD/CD Writer ($16.97 @ Outlet PC)
Total: $496.56
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-03-30 21:28 EDT-0400)
Comes with the AMD 125 watt heatsink, which is actually pretty good and its even better when lapped. For 30 bucks more you could get the fx 6300