I have 2 kids, neither are babies. The shows are on weekends so you take 2 days off + the weekend and you get a longer trip.
I went to Arcade Expo with 3 friends. We volunteered to tech at the show, got in free and got free meal tickets. We also shared rooms at the hotel total cost including gas was about $200 each.
I made sure league was on a good night for the family and made it a priority to go. I could be hanging out at a bar every night but instead my hobby keeps me home most night and I go to league and pinball shows.