Eddie, the guy we went with is having a hard time keeping up with demand and definitely needs to expand his business.
It is absolutely a growing trend. So far, I'm very happy and am really looking forward into making it what I want. Heck, with the generator I've got that I'm settin up out there, I've got my hurricane proof hideaway.
You could buy 5-6 of these for hardly any money and build a fortress. I'd partially bury them for insulation. Be pretty easy to get off the grid with 'em.