jtabb1256 :
I agree with your statement, but he hasn't said exactly what he's doing. Working with UE4 could mean a small turn-based game or a massive open-world game.
Personally, my laptop's i5 3210m does well enough at compiling the programs I write, but if he's used an i7 4790k before and wants more, the i7 6800k probably won't offer it. I have a 6800k @ 4.2 GHz, and the i7 7700k beats it at a lot of things.
If he has the money and knows that he wants a lot more performance, I don't see why he shouldn't just go for it and get the top-tier stuff.
True. But it's wise to spend it on something else. With extra money, you could spend it on other things such as software, games, furnishing, food, pet, bills, and etc, or even add it to savings. You could also donate it to charity with that extra cash. You don't need more than what you're doing.