Crysis 3 at max will require a good 750 dollars.
http://pcpartpicker.com/user/PCunicorn/saved/1GSn
Don't get Windows 7, W8 is the new standard. This will max out Crysis 3, you could downgrade the HDD for and save only 15 bucks.
http://www.youtube.com/watch?v=Xuj6P8rcJ7o
The 280X is a 7970 GHz edition, the 270X is a 7870 GHz. So the GPU is better on OP's, but most everything else is worse.
The motherboard in the build I put up.
Well it's pretty rubbish for overclocking and Biostar is a brand I try to avoid.
Your build is really quite unbalanced. You get an FX-8350 and a 7970 and then you go and get a 40 buck Biostar motherboard?
You should really spend a bit more on the board, just so you get something a little nicer.
Don't bother with the 8350 either, get the FX-8320 instead and save some money.
I don't feel like a 270X would max it out. My 7850 runs it on my medium and a few high settings, and I'm running at a lower resolution too.
And on top of that he only wants 30fps+ which is less than what most gamers want (around 50)A 270X is signifigantly better than a 7850, annd I have seen Crysis 3 run with max on 1080p with a 270X.
Quality. The lowest end motherboard you should get with a 8320/8350 is a Gigabyte GA-970A-UD3 or the MSI 970A-G46 Unicorn recommended. Don't go cheaper than those two.
If you bought a Sempron 145 (1 core CPU) you could choose pretty much any motherboard out there, but I would still only recommend ASUS, MSI or Gigabyte.
A 270X is signifigantly better than a 7850, annd I have seen Crysis 3 run with max on 1080p with a 270X.