Why though ? What’s the logic behind not just buying it pre-built ?
its a fair question – as i see it:
pros: better spec, nothing needs changed from day one, build and fettle it so its perfect from day one, opportunity to come in a bit under budget depending on deals
cons: a bit more hassle to research / find the right components, might need to borrow / buy tools, may require things like brake bleeds, possibility of properly breaking something