PCPartPicker part list:
http://pcpartpicker.com/p/xtYGD3
Price breakdown by merchant: http://pcpartpicker.com/p/xtYGD3/by_merchant/
CPU: AMD FX-6300 3.5GHz 6-Core Processor ($93.95 @ SuperBiiz)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($29.75 @ OutletPC)
Motherboard: Gigabyte GA-970A-UD3P ATX AM3+ Motherboard ($78.99 @ SuperBiiz)
Memory: G.Skill Ripjaws X Series 8GB (1 x 8GB) DDR3-1866 Memory ($54.00 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($47.99 @ NCIX US)
Video Card: Sapphire Radeon R9 270 2GB Dual-X Video Card ($142.98 @ Newegg)
Case: Cougar Solution (Black) ATX Mid Tower Case ($38.99 @ SuperBiiz)
Power Supply: Corsair Builder 430W 80+ Bronze Certified ATX Power Supply ($34.99 @ Micro Center)
Total: $521.64
This should be able to play games at 1080p at 60 fps.