You think a Prada bag costs <whatever a prada bag costs> because it's super good at holding things? It's not about sound, it's just exclusivity and hero worship and investment -- not things exclusive to blackmachine. Basically everyone bought them trying to sell them for more -- that quilt one was Fred's. Fred sold it for like $12k or something. Francesco had it, and was asking $20k for it. Now some other guy has it, and is asking $30k. It's just how it goes -- no one knows how much money these things are actually moving for because they're mostly sold privately. If he sells for $30k it's kind of like, good for him for knowing a good investment. If it sells back down to $12k, sucks for that guy for getting in at the wrong time, etc.
I expect the price to drop bit, in the fact that all the artists have pretty much moved on, there are a lot more erg options, public dissection of some 2008/2009 blackmachine has been done and the quality was pretty bad, etc. . I mean, there was a time when almost all of my friends wanted a blackmachine, now only one wants one and hasn't had one. Most everyone that wanted a blackmachine has owned one at this point. Everyone I've talked to has said good things about the more recent ones -- not comparatively exceptional things, but good things nonetheless.
But yea, he doesn't have other people build them. Feline Guitars builds the B6 models (ash body/top that cost like $3500), and these the guy is selling are all Doug-made ones.