I would have killed to play carnival games like that when I was a kid but they were absolutely strictly forbidden, because 1) they are obviously not worth the price (scam) and 2) prizes are just junk that we didn't have room in the house for anyways.

You can just say no. I have never played a single one of those types of games in my life because once I was old enough to work I understood my parents point of view. I'm actually thankful for them teaching me these sorts of lessons no matter how much I hated at the time. It's actually okay to not allow your children participate in cons and scams.