ASUS M5A97 R2.0 AM3+ AMD 970 SATA 6Gb/s USB 3.0 ATX AMD Motherboard with UEFI BIOS
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131873
$94.99
Pretty good mobo for the $$$.
AMD FX-6300 Vishera 3.5GHz (4.1GHz Turbo) Socket AM3+ 95W Six-Core Desktop Processor FD6300WMHKBOX
+ $10 off w/ promo code EMCWVTJ23, ends 1/8
http://www.newegg.com/Product/Product.aspx?Item=N82E16819113286
$119.99 (minus the promo code $10) = $109.99
$204.98. plus tax. Free shipping for both items.
The 7970 is a pretty fast and powerful video card so you may end up overclocking the cpu a bit to get full benefit of the card. Going with an i5 and appropriate mobo would be a bit better choice, but your are budget limited. My wife has the 6300 in her PC and I am truly impressed by its performance.