I have been pricing bardominium kits for years now, and that is not where the cost is here.
See, I already own the land, so I can't just drop everything and move to the flyovers.
In my county, a foundation slab is Required for any and all occupied permanent structures, no exceptions. Wells run $15,000 to $20,000, a three bdrm septic runs $25,000 to $50,000, almost all plumbing connections have to be done by a qualified pro, and that's before you get hosed by the local PUD for a power pole, transformer, and line at anywhere between $15,000 to $45,000, depending on easements.
And then, after all that, I'm still stuck with an ugly low-peak-roofed box that looks like a garage- and no amount of DIY is going to fix that.
I know you mean well, but barndominiums are just as much a meme as thos $2,000 Chinese mini-trucks were a few years back.