What if you're the ploughmaker? Do you either 1) sell the ploughs at such a high price that nobody can afford them; 2) lease them to people for a sizeable fraction of their product as yearly rent?

Under capitalism, if you're a ploughmaker, you do "what the market will bear."  Socialism, as Marx pointed out again and again and again, is not some impossible state of affairs where all exchanges are "fair."

"Imagine all the people/ Sharing all the world" -- John Lennon