PCPartPicker part list:
http://pcpartpicker.com/p/3Drxw
Price breakdown by merchant: http://pcpartpicker.com/p/3Drxw/by_merchant/
Benchmarks: http://pcpartpicker.com/p/3Drxw/benchmarks/
CPU: Intel Core i5-4570 3.2GHz Quad-Core Processor ($189.99 @ Newegg)
Motherboard: ASRock H87 Pro4 ATX LGA1150 Motherboard ($78.36 @ Newegg)
Memory: A-Data XPG V1.0 8GB (2 x 4GB) DDR3-1600 Memory ($64.99 @ NCIX US)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($56.99 @ NCIX US)
Video Card: Zotac GeForce GTX 780 3GB AMP! Edition Video Card ($498.99 @ SuperBiiz)
Case: NZXT Source 210 (Black) ATX Mid Tower Case ($32.99 @ Micro Center)
Power Supply: EVGA 600B 600W 80+ Bronze Certified ATX Power Supply ($59.67 @ OutletPC)
Total: $981.98
don't know if you need an OS or not.