Quote from @Joshua Stewart:
There will always be a few success stories with them here and there, and believe me I am interested in doing them myself, but the reality is much of the pricing that gets tossed around with these are either target prices (meaning we'll get there if there is large demand and we can scale) or the price is misleading because it doesn't include things like delivery, site installation and sometimes doesn't even include interior finishes at all.
Yeah the whole fiasco with Katerra was most discouraging. Could be they tried to do too much too soon. Elon Musk talks about how every startup needs to first take baby steps, to start out small so you only have to correct small mistakes. I actually think the solution might be a hybrid of mobile and modular. Mobile seems perfect for the small stuff, for bedroom, bath, kitchen, dining where you can install appliances, hvac, electrical, and plumbing in the factory - supplemented with a kit based barn style garage and storage with large open plan living room above. Anyway thanks for your input.