Thrumps biggest money maker now is using the Thrump name more then building things. When he does he doesn't use his own money.

There was one building he bought it was like buying a foreclosure he got the building for peanuts. Then renovates and sells it for billions or rents the rooms for millions.

Small time realtors do it all the time. But they use their own money and don't do it on Thrump scale.