Uhhh, so the right time to check is when the game doesn't matter and there's no obvious black mark on the brim of the hat?
https://www.mlb.com/news/giovanny-gallegos-hat-taken-by-umpires-in-cardinals-win
IMO they are a bit overpaid, at least on the top end, but the minor league players are drastically underpaid. Most of the owners likely wouldn't own teams if they had no financial incentive to do so. They also potentially risk billions.