PCPartPicker part list:
http://pcpartpicker.com/p/2fYz3
Price breakdown by merchant: http://pcpartpicker.com/p/2fYz3/by_merchant/
Benchmarks: http://pcpartpicker.com/p/2fYz3/benchmarks/
Motherboard: Asus M5A78L-M/USB3 Micro ATX AM3+ Motherboard ($44.99 @ Newegg)
Memory: G.Skill Ripjaws Series 8GB (2 x 4GB) DDR3-1600 Memory ($49.99 @ Newegg)
Storage: Seagate Barracuda 500GB 3.5" 7200RPM Internal Hard Drive ($49.99 @ Newegg)
Video Card: MSI Radeon HD 7870 GHz Edition 2GB Video Card ($139.99 @ Newegg)
Case: Antec One ATX Mid Tower Case ($29.99 @ Newegg)
Power Supply: Corsair Builder 430W 80+ Bronze Certified ATX Power Supply ($24.99 @ Newegg)
Total: $339.94
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-12-06 12:02 EST-0500)