She [an artist] tries to do a show a year, one every three years at each of the three galleries. The idea, she explained, is for your prices not to have a sudden rise, precisely because they can crash, but rather for your dealers to increase them slowly as your work receives exposure through venues like group shows, exhibitions, and biennials. Auctions can be dangerous for just that reason. At the time we spoke, Wilcox’s works on paper (19″ x 24″) were selling for around $6,000; her largest paintings (12′ x 6′), for $45,000. Dealers take 50 percent. Prices are based on size, not judgments of quality, because you don’t want to influence buyers’ opinions. Smaller works are cheaper, but more expensive per square inch (kind of like real estate). Large paintings are easier to sell in Los Angeles than London or New York, because the houses are bigger.
That is an excerpt from William Deresiewicz, The Death of the Artist: How Creators are Struggling to Survive in the Age of Billionaires and Big Tech, an excellent book (ignore the subtitle).