If you want a comfortable frame rate at 50-60fps you can play the game in 720p resolution. Rather than on full HD. If you set it at Full HD you get around 30-40fps which will be sluggish if you are moving around.
According to the Video below. His running on a i3 with 750ti. Which leads to a maximum core loading of 9X% when gaming. So basically if you are going to put in a higher end GPU in future for anything more stressful games it might be bottleneck.
Our dear forumer here is using an i7 quad core and his already receiving about 55% loading.
https://www.youtube.com/watch?v=1EV8iMMv7JA
https://www.youtube.com/watch?v=h3R19XaO2cc
Note that i find it strange that he reset everything to default again.
But among all the settings, most of them would highly recommend a 8gb ram. Not unless 4gb and you got no programs installed running at the backgrounds. Which i highly doubt it will happen.
ASRock H81M HDS + i5-4460 ~ $297
Crucial 8gb 1600mhz Value Ram ~ $78
WD Blue 1tb ~ $70
Sapphire r9 280 3gb Dual X ~ $235 (Use 18M1ANNIV code in lazada to enjoy a max capped of $50 discount)
FSP Hexa 550w 80+ PSU ~ $69
Cooler Master Elite 311 ~ $55
LG DVD Drive ~ $21
Total ~ $825. Buy at tradepac. DIY <------ Please ask for more discounts.
This the best you should have without any hiccups.