voila with ur case u selected. u cant do more within ur budget. pretty solid and added windows 7 also.
PCPartPicker part list:
http://pcpartpicker.com/p/2964i
Price breakdown by merchant: http://pcpartpicker.com/p/2964i/by_merchant/
Benchmarks: http://pcpartpicker.com/p/2964i/benchmarks/
CPU: AMD Athlon II X4 750K 3.4GHz Quad-Core Processor ($79.99 @ Amazon)
Motherboard: MSI FM2-A55M-E33 Micro ATX FM2 Motherboard ($29.99 @ Newegg)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1866 Memory ($52.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($58.98 @ OutletPC)
Video Card: Asus Radeon HD 7850 1GB Video Card ($104.99 @ Newegg)
Case: Rosewill CHALLENGER ATX Mid Tower Case ($49.99 @ Newegg)
Power Supply: EVGA 500W 80+ Bronze Certified ATX Power Supply ($29.99 @ Microcenter)
Optical Drive: Asus DRW-24F1ST DVD/CD Writer ($15.99 @ Newegg)
Operating System: Microsoft Windows 7 Home Premium SP1 (OEM) (64-bit) ($89.00 @ Amazon)
Total: $511.91
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-11-26 15:33 EST-0500)