Has anyone had or been to a party at The Cradle of Aviation Museum?

I'm confused about their pricing. Its $350 for up to 25 people. They said they dont charge for adults unless they step into the museum during the treasure hunt. But their not allowed to stay or go into the museum after So basically your paying $7.50 if the parent wants to do the treasure hunt with their 5 yr. old??? That doesn't seem fair.