PCPartPicker part list:
http://pcpartpicker.com/p/sasC
Price breakdown by merchant: http://pcpartpicker.com/p/sasC/by_merchant/
Benchmarks: http://pcpartpicker.com/p/sasC/benchmarks/
CPU: AMD FX-6300 3.5GHz 6-Core Processor ($129.99 @ Amazon)
Motherboard: ASRock 970 Extreme3 ATX AM3+ Motherboard ($74.99 @ Newegg)
Memory: Mushkin Blackline 8GB (2 x 4GB) DDR3-1600 Memory ($35.57 @ NCIX US)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($64.99 @ NCIX US)
Video Card: XFX Radeon HD 7850 1GB Video Card ($162.55 @ Newegg)
Case: NZXT Gamma Classic (Black) ATX Mid Tower Case ($34.99 @ Amazon)
Power Supply: Corsair Builder 500W 80 PLUS Bronze Certified ATX12V Power Supply ($39.99 @ Newegg)
Optical Drive: Lite-On iHAS124-04 DVD/CD Writer ($17.99 @ Newegg)
Total: $561.06
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2012-12-12 14:37 EST-0500)
It's a little over your budget.
edit: changed the mother board. You can further reduce the cost by getting a 500gb HDD but won't make much difference.
PCPartPicker part list:
http://pcpartpicker.com/p/sazW
Price breakdown by merchant: http://pcpartpicker.com/p/sazW/by_merchant/
Benchmarks: http://pcpartpicker.com/p/sazW/benchmarks/
CPU: AMD FX-6300 3.5GHz 6-Core Processor ($129.99 @ Amazon)
Motherboard: ASRock 960GM/U3S3 FX Micro ATX AM3+ Motherboard ($61.97 @ Newegg)
Memory: Mushkin Blackline 8GB (2 x 4GB) DDR3-1600 Memory ($35.57 @ NCIX US)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($64.99 @ NCIX US)
Video Card: XFX Radeon HD 7850 1GB Video Card ($162.55 @ Newegg)
Case: NZXT Gamma Classic (Black) ATX Mid Tower Case ($34.99 @ Amazon)
Power Supply: Corsair Builder 500W 80 PLUS Bronze Certified ATX12V Power Supply ($39.99 @ Newegg)
Optical Drive: Lite-On iHAS124-04 DVD/CD Writer ($17.99 @ Newegg)
Total: $548.04
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2012-12-12 14:44 EST-0500)