If this were done by professional crews in a mass production manner in developments, we could build these at a production cost of 40-70K with say 12 base models.

A builder mark up of 25% would put them delivered at 50-88K. Make the avg lot size .25 acre - .5 acre and you could still deliver them with land in many areas for sub 100K all in.

Why can't that happen, one word answer, GOVERNMENT. Who claims to want to solve problems like poverty and homelessness.