I recently built my own and I agree with all that's been said.
I spent ages working up to it. Doing little things on my old one. Gradually doing more ambitious upgrades until I'd done virtually all the processes involved in a build.
I'd also followed this forum and other sites such as Tom's Hardware and looked at comparisons between the relevant components.
Also looking at the websites of custom builders and their various mid and top end combinations can give you an idea of what's being paired with what out there.
Problem is there is always a better graphics card coming. Always.
My best choice was an enormous case with a slide out motherboard tray. This made the whole build so much easier.
Also recommended. I had my old pc running and was able to beg for help on this forum when I got stuck.
I'll certainly never buy one off the shelf again