I built my own computer and to be honest it really isn't that hard.
The nice thing about building your own computer is you can completely customise the specification yourself depending on your needs.
If your thinking about building one then this is the best website for checking all the parts are compatible:
Hope this helped.
My PC Specs which work very nicely on ETS and for editing videos:
Processor: Intel Core i5 6500
GPU: Gigabyte GTX 1060 3GB
RAM: 16GB DDR3
Storage: 128GB Toshiba SSD, 2TB Tosiba HDD
Fans: Corsair Air Series AF120 Quiet Edition High AirflowFan
Case: Corsair Carbide Series 100R