I bought a cheap property (vacant land with no utilities) then built the house literally $20 or $1000 at a time buying blocks/wood/pipes etc as I was building. All the money was legally earned and taxed, but the point is even the title company was sidestepped in this case beyond an amount pretty trivial in comparison to the value of the property and very little of it would have had to of went through the traditional financial system in order to make it possible.