[BETA] The Sims 4 History Challenge

Hey, I have a clarification question. I totally understand paintings not being sold in the Prehistoric Times, and would also understand them not being sold in Early Civilization. But paintings are never explicitly allowed to be sold at all until the Modern Day, when selling restrictions are unlifted in full. This doesn't make sense to me - are paintings allowed to be sold before the Modern Day? I would assume so, if not in Early Civilization, perhaps in the Middle Ages when the Painter Extraordinaire/Patron of the Arts aspiration/career unlock? Or are we not allowed to sell paintings because they can become worth so much money for the amount of time spent on them?