> Cost and labor are two different things, especially for people whose market assign very little monetary value for their labor

Plus the fact that many places (including the US) have tax burdens >= 50%.

So if it would cost $50K to hire a contractor to build a minimal house (labor + materials), we'd have to first sell $100K of our own time.

On top of that we'd be be fighting an uphill battle against inflation and land scarcity.

So it really doesn't take much for this kind of thing to be worthwhile.