I knew a seller - a veterinarian in Missoula, MT - who purchased a trailer, then sold it on owner financing, and repeated the process many times as his buyers defaulted.

Even at the lowest income bracket, there are buyers who can put together 10% down on a $12,000 house - even some who can put together 20%. If you owner finance such a sale, and charge interest rates that make the monthly mortgage competitive with rent elsewhere, you can do very well for yourself.