I believe my system is adequate. Without Windows 7, it is only $527 AUD.
PCPartPicker part list:
http://au.pcpartpicker.com/p/8Tz623
Price breakdown by merchant: http://au.pcpartpicker.com/p/8Tz623/by_merchant/
CPU: AMD Athlon X4 760K 3.8GHz Quad-Core Processor ($90.00)
Motherboard: MSI A78M-E35 Micro ATX FM2+ Motherboard ($75.00 @ Centre Com)
Memory: G.Skill Ripjaws X Series 4GB (2 x 2GB) DDR3-1600 Memory ($31.00 @ CPL Online)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($62.00 @ Centre Com)
Video Card: Asus Radeon R7 260X 2GB DirectCU II Video Card ($155.00 @ PCCaseGear)
Case: NZXT Source 210 (Black) ATX Mid Tower Case ($50.00)
Power Supply: Corsair VS 350W ATX Power Supply ($45.00 @ CPL Online)
Optical Drive: LG GH24NSB0 DVD/CD Writer ($19.00 @ CPL Online)
Total: $527.00
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-09-09 13:33 EST+1000
It can play Battlefield 4 at 48FPS on High settings at 1080p.