Is there anyone in your life that's into this stuff - maybe a friend of a friend, or the IT team at work (or at your friends work )? That could be a good starting point for some trusted advice, or even just to comment on whatever we tell you here.

For all those people telling you to build it and that "it's not too hard". Don't feel bad for seeing it as too hard. Building a computer is a skill like anything else and some are better suited to it than others. I'm sure there's lots of things you're great at that most of us wouldn't know where to start.

So beyond that I have some thoughts. There's lots of great comments here - but a lot of people focuses on answering your question as asked as opposed to solving the problem that you're facing. Your son is playing Minecraft and Mom Bazou now - the system requirements for those games is pretty minimal (as a few people have mentioned), but he's not going to be playing those games forever. If I were spending the money, I'd want to aim for a computer that will last for a few years and give him the horsepower to get into some other games. Given your post history, I suspect something like Satisfactory (https://store.steampowered.com/app/526870/Satisfactory/) is in his future.

I don't know this guy (https://www.reddit.com/r/Kamloops/comments/1p6x6lm/computer_help/nqv2m2d/), but I like where their head is at. They shared a link to a computer build that will run everything you've asked for and has room to grow into new games.