I heard a caller to Mad Dod lament the other day (it may have been the JT the Brick show) about a day/night doubleheader at I think Nationals where they clear you out so they can get 2 gates. But they charge full single game prices for 7 inning games.
If you stay at a ballpark for a doubleheader you should be locked up. Because you are a lunatic and a threat to society.
I attended many #tpt doubleheaders in my youth at Cleveland Municipal Stadium. Parents would just let us run wild, and they would sit in the seats and drink some beers. Slice of Americana, really.