I have many fond memories from my childhood of getting ice cream with my friends and parents. None of them involve a trip to the supermarket.
You say Over-Priced. I say Priceless.
I do too. It was exciting the one time or so every month the parents would give us money for the ice cream truck.
I would say the markup is more egregious at baseball stadiums and movie theaters.
And yes I had to pay cause my kids wanted it.
You CHOOSE to go to a ball game, theme park or theater KNOWING that their prices are inflated. You are within your rights to eat before or after the event and in most cases, people are sneaking in items without fear of reprisal. Mothers can hide food n' drinks in their baby bags or purses and dads can use the old fanny pack!
And if in fact your children are so entitled that they can squeeze you so easily for overpriced goods, then it is your own doing for taking them. Not saying you're a bad parent, but you are essentially asking for it by making the trip. All the while, the wife is poking you in the back saying "C'mon honey, we're on vacation!"
But this is capitalism at it's finest, the notion we should give more money to people for things that are priced less elsewhere because it's "fun." So if you can afford it, then buy it and enjoy it!