Originally Posted by
Endus
Marx's utopia was an abolishment of ownership, not a market-based system of worker collectives.
Socialist theory neither started with Marx, nor did Marx sum it up. He was just one influential writer with a particular outlook, who's more important for his critiques of capitalism than his own economic theory. If you hear something socialist, and you think to yourself "sounds like Marxism", you don't have even the most rudimentary understanding of socialist theory to understand the conversation .
You should be looking for names like Adam Smith, John Stuart Mill, Pierre-joseph Proudhon, and more broadly, John Rawls, if you're trying to get a grasp on market socialist theory.