What do you do ? I understand what you mean bang for the buck but the thing is let me explain this.
I can pretty much put my life on the line your CPU you have now has not gone to 100 percent throttle. Even rendereing video or audio it will not use 100 percent and games use 30 percent to 70 percent on your CPU. You are not going to see a difference with a i core chip, your already soo fast. Trust me on this no need to waiste money when the CPU you have now has never gone to full throttle,, that means you dont need a upgrade until your 100 load then u can say ok let me get a new processor with 8 cores.
I promise you will not see a difference in anything. Stick with yoru current rig my friend
My rig was born Nov 21 2007 ,, for DAW and gaming . Im a music producer and it has never gone over 67 percent, that was on a audio render.
BTW this applies for CPU being OCed or NOT.
Just chill relax, like many others should do and wait. I will never understand a Qxxx upgrade to i series.. As if you do anything important like render or something. lol
I am also happy to say I will never upgrade, until the time comes where there is a GPU inside a CPU chip . and thats 2020 lol nvidia and ati would be out of buseiness lol