It's been said allready, get a cheaper CPU and more expensive GPU. Games like Fallout 4 don't require very strong CPU since there's not that many things to process. graphics settings though require good GPU. All games apart from some heavy strategy games don't even require much of an CPU these days especially console ports. CPU is the part that ages the slowest in a PC. GPU on the other hand is a part people switch the most when they want to use Ultra-settings + 60FPS, years after.
oh! and wait for DX12 capable GPUs to come out or get some of the upper end Nvidia cards since they have full support.
Here's about the support levels http://www.extremetech.com/extreme/207598-demystifying-directx-12-support-what-amd-intel-and-nvidia-do-and-dont-deliver you only get basic level support with AMD 1.0 GCN cards, 270X is GCN1.0.
and I agree with people here that you could use a cheaper mobo, there's usually one or two budget ones that give you some upper end tech for 60-80$. You might even find a deal on crossfire/SLI mobo for this price, if you want to get another GPU for more muscle in the future. Though remember to calculate the power usage so your PSU is enough.
I will gladly recommend Thermaltake V3 or V4 for a budget-case, I have one V3 and they are light-weight full-sized cases so you can easily move them around too if you ever get into the LAN scene and still want a full sized case, or you travel a lot and want to take PC with you.
