Get a Z170 board with skylake core i3 and fast DDR 4 ram 2666 mhz or above. This will be in budget and as a surprise you can bclk the core i3 to 4.4 or 4.6 ghz and at those clocks the cpu beats stock performance of core i5 2500K, fx 8350 and everything below by a fair margin. Which litreally means u can run all games on 60 fps and even the r9 380x in crossfire mode wont bottleneck it.
This will help u get the latest intel chip so u will get good resale value in future. Secondly ur rig will be more future proof, you can add a core i7 or core i5 later on. Plus cpu supporting the z170 board will be in abundance in the market till 2018-19, since its quite new.
Don't get me wrong on this the fx are great cpu and still gets u 60 fps in most games. I am myself using fx 8320 (4.4 Ghz oc), they are now getting aged plus their pricing though less were great a year back but not now, due to competition.