You mentioned taxes in your post.
There are states that all have different taxes. I get that, "state" taxes vary.
I was RV'ing around the Midwest and then headed South. I felt CG's fees where acceptable cross the board UNTIL I hit my first Florida CG!
First of all my bill FAR exceeded what the advertised rate was.
Well when I asked why it was so high I got a "Bed Tax" 101 lesson. :B
Yup the bed taxes normally only applied to hotels is also applied to CG's in Florida! They figure you are sleeping there albeit in your OWN bed so they charge bed taxes. :R
So by the time you add the state tax and the bed tax, your 30.00 a night CG rate is now substantially higher.
So when discussing CG rates 'across the USA', there is a ton of variables. Not necessarily related to what the amenities of the CG are.
Full timing and snowbirding where you are traveling thru areas you are not familiar with versus a pre planned reserved destination trip exposes you to all types of CG's!!
I just got sick and tired of pulling into a CG after a long day of driving to find out it that looked like Night of the Living Day and it being too late to go look for another one!
So for that reason I do stay at KOA pretty much exclusively if I can find one on my route. I think they are really pretty much in line with other CG's average cost per night. And at least I know what I am going to be pulling into when I come off the road for the night.