Its 20 dollars a day here at our local tennesse state parks near knoxville. I have paid more than that at a KOA and I didnt mind because of the amenities, but I dont think for a regular camping spot with elect and water I would pay that, at least not for the state parks here. It might be helpful to others if you wrote a review of the parks you visited so we might get some idea what people get for their money.
Teaspoon