The youth league here has bumpers for 2-4 year olds. They bowl one game and just pay the league rate. If they are up to it they may bowl a second game. The house hasn't been charging us for shoes during league.
Then at 5 years old they start the next age group and no bumpers, play three games, and weekly $10.
Both are USBC sanctioned, but during summer they are just doing coaching clinics. New season starts about two weeks after local schools are back in session.