Sometimes I get sticker shock from seeing what campgrounds charge, especially private ones that cater almost exclusively to RVs. Although if at all possible, I avoid staying at an RV park.

In the immediate area, we have one park with primitive sites for $13/night. To me, that seems pretty reasonable. I would have balked at the price 20 years ago, but everything was cheaper 20 years ago. A campsite without electricity, but in the part of the campground that has running water and showers will cost $20/night. It's survivable, but if I can stay under $15, I feel like I'm getting a deal. The one, non-state park I've stayed at within a day's ride is $6/night for a tent.

Just took a little, extended trip.
1st night camping -- free. Technically I stealth camped because I couldn't find the legitimate campsite, but the legit site was free, too, for anyone riding/hiking the trail I was on.
2nd-5th night -- I think I paid $40 for 4 nights. But I also think that included wood and ice.
6th night -- Free camping at a state forest
7th night -- airBnB, about $70, I think
8th night -- free campsite along the trail
9th night -- $28. Most expensive camping of the trip.
10th night -- $10

So, apart from the times I had a roof over my head, I did okay, averaging less than $10/night. I do agree that campsites can be pretty pricey, but maybe they don't have to be depending on where you are.