[harmmonica]

Absolutely possible. 50k for a 400 SF house that's built to modern code given those things you mentioned are already in place. To be specific, that's a full kitchen, with decent appliances, a full bath, 1 bedroom (though you _could_ fit 2 in 400 SF), a living room and some storage space.

Not that it helps to write checks you have zero way of cashing, but we just built this: https://imgur.com/gallery/KbPlbPR/comment/2099542904. We're still working on the interior, but this design, if we increased its size to 400 SF, and given the things you mention being in place, could be had for 50k or less even, and it would be built better than most homes in the US.

Just one guy's take, but my friend and I are trying to realize the dream of building more affordable housing that doesn't compromise on quality and design. We're just starting with this one project, though, so obviously a long way to go!