What are your full system specs? It may be that the rest of your system may bottleneck a good graphics card making getting anything decent graphics card wise pointless.
PCPartPicker part list:
http://pcpartpicker.com/p/2cWWQ
Price breakdown by merchant: http://pcpartpicker.com/p/2cWWQ/by_merchant/
Benchmarks: http://pcpartpicker.com/p/2cWWQ/benchmarks/
CPU: AMD FX-6300 3.5GHz 6-Core Processor ($109.00)
Motherboard: Gigabyte GA-970A-DS3P ATX AM3+ Motherboard ($80.00)
Storage: Kingston HyperX 3K 120GB 2.5" Solid State Disk ($110.00)
Storage: Hitachi 500GB 3.5" 7200RPM Internal Hard Drive ($50.00)
Video Card: EVGA GeForce GT 630 1GB Video Card ($63.00)
Case: Cooler Master Storm Scout 2 ATX Mid Tower Case ($70.00)
Power Supply: XFX 550W 80+ Bronze Certified ATX Power Supply ($25.00)
Optical Drive: Lite-On iHAS124-04 DVD/CD Writer ($12.00)
Operating System: Microsoft Windows 7 Home Premium SP1 (OEM) (64-bit) ($67.00)
Other: Old Poo Kingston 4x1 4gb 1066mhz (Purchased)
Total: $586.00
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-12-17 17:15 EST-0500)
Thats my specs right now. getting 8 gigs hopefully this christmas