HELP with Builting a pc!

Whoever left the CX500 PSU in there, obviously doesn't know quality of that PSU.

PCPartPicker part list / Price breakdown by merchant

CPU: AMD FX-6300 3.5GHz 6-Core Processor ($94.89 @ OutletPC)
CPU Cooler: Cooler Master Hyper TX3 54.8 CFM Sleeve Bearing CPU Cooler ($17.99 @ SuperBiiz)
Motherboard: Asus M5A97 R2.0 ATX AM3+ Motherboard ($84.99 @ NCIX US)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1866 Memory ($64.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($49.98 @ OutletPC)
Video Card: PowerColor Radeon R9 270 2GB TurboDuo Video Card ($133.98 @ Newegg)
Case: Thermaltake Commander MS-I ID ATX Mid Tower Case ($29.99 @ Micro Center)
Power Supply: XFX 550W 80+ Bronze Certified ATX Power Supply ($38.98 @ Newegg)
Total: $515.79
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-02-17 05:10 EST-0500

Brother, this is your best build. The 270 beats the 750, and has an extra gig of VRam. Also, the MSI 970 isn't needed, a decent and cheaper Asus board is better.