I quote:
"I would say get a good future proof motherboard first and then start adding bits and pieces"
I respectfully disagree, brother.
Well... Yes, 2nd and 3rd Generation Intel Processors are quite a bit outdated but the thing is, a game relies on GPU much more than CPU!
Try running a modern game on the top of the line 4Ghz i7 and it will run choppy if you GPU isn't up to the task! Hence, hardcore PC builders spend almost 75% of their budget on a GPU and the rest of it goes to the WHOLE system!
A system DOES matter, but not as much as The GPU!
Look at the system requirements of Resident Evil 7 which, BTW, has very realistic graphics and it says:
CPU: Intel i5 4460 (4th Generation) 2.7Ghz.
GPU: Nvidia GTX760.
RAM: 8GB.
This particular processor is basically a lower-mid range CPU in Intel's line-up, but it's up for the task!
So...
Get a future proof GPU and then start adding bits and pieces!