Also, amp that RAM up to at least 16GB, and use a smaller SSD for OS and get a large HDD for your games and shit. If you're willing to pay more, you can get a large SSD for your games as well and they will load super fast, yo. And yes, get a better graphics card.
This is everything I was going to say. 8 Gb Ram is more than enough. Ram is cheap so why scrimp. Yep, you don't need 256GB for an SSD. Get a 64Gb one for your OS and stick everything else on a big HDD. That case is rubbish. Why do you need something so big?
I had a 3.3Ghz i3 in my last PC. Its a great chip. You won't notice the difference in an i5 or i7 for most games.
You definitely don't need 500W of power supply with a 4th gen i3, an SSD, 4 GB of Ram and a single budget graphics card. Are you cold or something?
Nvidia's PSU requirement for the 750 Ti is also low at just 300W, so you won't need a beefy 500W or 750W beast to power this mini GPU.
Also, what do you need a gold power supply for? Because it says 'gold' and that sounds better so its worth paying more? Is energy that expensive in the US? The difference between a 'gold' power supply and a silver is 2-3% efficiency.
https://en.wikipedia.org/wiki/80_PlusThe difference in your wallet will be about 20 bucks.
You can save a bunch of money and have a better system by doing a bit of proper research.