Hi Pete, thanks for demystifying that a bit.
Your
answer was informative, but also, for me, a bit disheartening. Earthships and Earthship-inspired homes often come with the tagline "and if we can build these in the harsh New Mexico desert, we could be building them anywhere!"
For nearly a decade, I've dreamed of building an Earthship-inspired home. I fantasized about how I'd build it so cheaply because I'm good at scavenging and reclaiming trash...but as I learned more about construction I realized materials aren't where the major costs come from in building a house, or most anything else. It's labor.
Well, tight little communities of "crazy" friends who are into alternative off-grid building and have free time are
not everywhere (that's part of what makes those communities so cool!)--as you said, "a lot of people aren't in positions to have 'work parties' with friends doing similar things"--so the tagline probably isn't true, at least not if Earthships are to retain their advertised quality of being more cost-effective than conventional construction.
That's the sense I get anyway. Maybe this is an opportunity for someone to become a specialized "Earthship build party organizer"--such a person could make a career going around from place to place rounding up cool
local people who want to help out wherever someone wants an Earthship built.
But for now it seems, the only way to build an Earthship "on a budget" is to build it near a bunch of other people with free time who are also building them.