Someone told us to look for rv parks without swimming pools, playgrounds, saunas, etc. and to look in the Good Sam or equivalent RV/Campground yearly publications for those rv parks/campgrounds kinda a bit farther from cities/tourist areas .. we have done precisely that and have been happy with those with fewer amenities to stay in and enjoy. When going to New Orleans we stayed near Kenner at an rv park with a twice daily shuttle into town and back .. the only places we have had to "bite the bullet" is places like Niagara Falls (both sides) in order to spend a few days at each place.
But for the most part have looked for "minimum amenities" places and have enjoyed our travels. And surprisingly enough some parks also have golf courses (with separate fees) and were very affordable ! And we don't do golf, just enjoyed saving a few bucks. Shalom.
