Yes, drives are going to fail. Yes, power supplies are going to burn out. Yes, god, you’re going to get new parts. Yes, you will have to actually talk to vendors.
Big. Deal. This shit is -not- hard.
For the amount of money you save by doing it like that, you should be clamoring to do it yourself. The concern trolling doesn’t make any sort of argument against it, it just makes you look lazy.