We have 6 of our own and often anywhere from 1-4 Foster kids. Our cost of living is high, and we don't go out to eat, ever! That's part of the idea of camping, it lets us travel when we really wouldn't be able to otherwise.
When we have just our 6 kids, if it's an extra $10 per night, then it is what it is. Call it large family tax or whatever. But when we have more than that, it really adds up. Or for the campgrounds that start charging you extra after 2 kids.
It's not that I wouldnt pay the $100 if there was a real reason to. The big Jellystone campground in northern Indiana would cost us $130 a night to go there. I'd consider it for a night or two because it's really a destination kind of place for a family with kids. But every little campground with little more than a grassy area and maybe a swimming pool thinks they need the extra $30 a night too, and that's where it starts to really add up.
I know state parks always say 6, but I've always interpreted that to mean 6 people or my whole family, so I'm glad to see that at least some areas have defined that as such.
Now the next problem is big family = big trailer, so that is going to limit us a bit also. I don't know if we'll always be able to get into state parks.
For now it just means a lot of extra homework calling around and asking questions bof a lot of different campgrounds to try to find something reasonable that can accommodate us.