Please help! Upgrading cpu & mob

Blake BLiZZY

Honorable
Dec 11, 2013
19
0
10,510
Current build-
Case:antec 1200
Mob:evga 790i ftw
Cpu: intel quad core Q9400 oc to 3.6ghz
Ram: 8gb
Gpu: gtx780sc
Psu: antec 850w

Want to buy AMD FX-8320 3.5 GHz (4.0 GHz Turbo) 8-Core Processor with MSi 970A-G43 mob from a guy on Craigslist. Basically brand new parts with receipt for 185. Will this be a better upgrade compared to the cpu and mob I have now. (Mainly Gaming) and is the price fair. Please help, not the best when it comes to pc's and upgrading. And right now my gpu is being bottlenecked but nothing to crazy.
Thanks guys, I plan on buying tomorrow if I get good feedback!