PCPartPicker part list:
http://pcpartpicker.com/p/X9gNgs
Price breakdown by merchant: http://pcpartpicker.com/p/X9gNgs/by_merchant/
CPU: AMD A10-7850K 3.7GHz Quad-Core Processor ($169.96 @ OutletPC)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($29.98 @ OutletPC)
Motherboard: Asus A78M-E Micro ATX FM2+ Motherboard ($64.99 @ Mac Mall)
Memory: A-Data XPG V2 16GB (2 x 8GB) DDR3-1866 Memory ($136.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($54.98 @ OutletPC)
Case: Rosewill Line Glow ATX Mid Tower Case ($39.99 @ Newegg)
Power Supply: Corsair CX 600W 80+ Bronze Certified Semi-Modular ATX Power Supply ($49.99 @ Newegg)
Optical Drive: LG GH24NSB0 DVD/CD Writer ($15.98 @ OutletPC)
Operating System: Microsoft Windows 7 Home Premium SP1 (OEM) (64-bit) ($84.99 @ NCIX US)
Total: $647.85
Prices include shipping, taxes, and discounts when available
This does not include a GPU, but you can purchase one at a later date when you have the funds. Meanwhile it does come with an APU that has an R7 on die. So you can play games at decent settings.