That would easily be 50% or $300 over budget.
And a i7 would be about 40% faster in ideal multi-threaded scenarios, barely faster in single threaded scenarios.
The 750 Ti is the weakest link, a 1060 would be about 150%, which is definitely worth the extra $110 price premium if you are going for the best bang for your buck. But still a 750 Ti will run UE4 well enough to make a AAA looking game, as long as you are okay with lower FPS and aren’t hitting the vram wall.