To be honest? Have a friend or a guy from lomcn help you set up an pc by buying parts from amazon then put it together with someone who you know has IT knowledge and it'll save you aloooooot of money . Only if you're playing to have the most high end pc which requires tons of cooling etc I'd go to some special website otherwise put it together yourself or with a friend.
This can easily save you up to
500-1000 bucks depending on what kind of price range you're looking for.
Small list of what you'd need
Case
motherboard
cpu (make Shure the CPU fits the motherboard so you have to look what slot both of them are)
Powersupply
cpu cooler(heat sink&fan or water cooled if you're going to do it yourself I'd suggest a fan cause water cooled is quite an issue on your own.)
Gpu
HDD
SSD(optional)
Cd/DVD /bluray drive
(depending on CPU cooler perhaps cooling liquid ,or thermal paste)
If you're looking to crossfire multiple GPUs make Shure your motherboard actually can do it instead of going full yard and screwing it up
Also if your gpu requires an extra power supply(have to plug pci-e 6/8 pin slot in it and are doing crossfire) make Shure your power supply has multiple of those pci-e cables
Goodluck