I'm thinking of building a PC over the summer. I will be buying parts little by little, and I wanted to know what I should buy together so i can test that everything works. I'm afraid of getting a bad part and not knowing until it's too late.
I would recommend buying all at once but that isn't always possible.
Motherboard, RAM, PSU and CPU allows you to check that they all work in an external POST.
Then GPU, as you can add that to your external build.
Then case, storage, aftermarket coolers, case fans etc can be bought last.
If you do do this then make sure to try and keep your components as dust free as possible.