As it stands, buying mining equipment is so opaque to an outsider that he's more likely to get scammed trying to get one. If I haven't read Mining for the Streets by Diverter and Econoalchemist's Mining blog, I wouldn't even have a lick of idea where to start.

There's a clear lack of open and accssible knowledge on this side of Bitcoin. It also doesn't help that there's only a handful of companies that actually produce the equipment.

If you're to ask me why Bitcoin mining got so centralized, it's because of those two factors.