Nats are one of the more expensive ballparks in MLB, no?
Anyway, at this point, minor league games seem the best option for taking kids to a game
According to an article dated July of 2021 in gobankingrates.com the top 4 most expensive were Wrigley Field, Fenway Park, Yankee Stadium, Nationals Park.
According to an article dated April of 2022 in mentalfloss.com Yankee Stadium pulled ahead of Fenway so it was Wrigley, Yankee, Fenway, Nationals.
I got a hot dog at one of the last games last year and the bun was stale. If you're going to be expensive you should at least be good.