It’s not clear to me why you think this isn’t supply and demand at work. Ford had a particular demand for labor, and the market had a particular supply of it. What you’ve described is Ford defining what he thought his business requirements were, making differentiation judgements about what kind of labor he wanted to hire, and coming to a conclusion about how much he was prepared to pay for it. The only factors I can see that would introduce inefficiencies to discovering an equilibrium price in this situation are that Ford was doing something brand new, so he perhaps didn’t know exactly what he had demand for, and he was doing it in the middle of the second industrial revolution, so the market conditions would have been changing perhaps more than usual.
Ford never said he intended to make money by only selling cars to his employees! Only that the employees should also be able to afford the cars they were producing.
