Obviously, 9mm and .45 are amongst the leaders in handgunning popularity and there are multiple bulk sources for jacketed bullets for these guys. And plated works awfully well for those who need some of the jacketed qualities that you don't get from cast lead bullets, and you can buy plated bullets in bulk. But there's a place where plated bullets have their limit and only jacketed will do and yet there are either none or extremely limited venues for bulk bullets. I'm talking about making purchases no smaller than 1,000 pieces and more commonly at around 3,000 pieces & beyond.
Precision Delta pretty much matches this to a T. Minimum orders of 2000, I know folks that order in quantities of 10k from them at a time.
The biggest problem with "bulk" bullets most of the time is that they aren't priced like bulk bullets. It's always a function of cost to the buyer.