I find these homes really attractive because of the price, modular nature and ease of delivery.
Trying to talk my wife into a blockhouse consisting of two levels of these arranged in a square with a courtyard in the middle. In the courtyard, of course, the entrance to the next shelter. The next shelter is currently under construction and will be four corrugated steel pipes with 12 foot diameter arranged in an "H" configuration. Across the top of the courtyard will be a meshed steel ceiling that admits light and bumble bees but little else. We could grow one garden in the middle and still have room for a swimming pool, cabana and outdoor deck. The top level would have a guardrail with steel plates on the outside so you could use it as an observation deck accessible by staircase from the inside. We might also have a deck on the inside accessible from the second floor.
I tell her we could do this entire thing for less than $100,000 total all on a concrete foundation and we'd have an earthly paradise inside of it but would be securely protected from the outside world in every way. The solar panels and wind generator could go on the roof.
She looks at me askance but she is coming around slowly.