This is the kind of thing I am interested in.
I made one for my so the Xmas before last. I wasted time and gasoline shopping the stores (all stores) for a nice new fast pc for him. Everyone was out of everything, except if ya wanted to pay top dollar, in advance, and wait for restocking.
For that, you can pay more for some pc infested with 'trialware' and all that garbage.
The thing is already obsolete by now, but still never crashes nor locks nor slows down, and is unholy fast.
I used this website to help, http://pcpartpicker.com
It checks prices for the piece parts and verifies that such parts will play nicely together.
It was as simple as taking a drink of water.
Everything involved, from buying the parts via different companies to the assembly and setting up.
All I did was simply throw the thing together and it worked flawlessly the first time and ever since.
I plan to build another for myself, this thing is way too slow for what I do.
Once I get caught up on some bills.
I highly recommend build it yourself. You get performance at a resonable cost. With none of this big box store issues going on.
The only improvement to that website I posted is to gain information from it, then buy your stuff on Ebay. Its generally cheaper.
They just compare prices among 'normal' dealers.