That past two years traveling all over the USA during several extended trips, we averaged less than $500 a month for campgrounds. Some free (not many) some discount with COE and NP pass, and some state parks. We do not 'scrimp', nor hide out in 'cheap' CG's either. We go where we want, see what we want, and have a good $$$ plan in place. We almost never go to private CG's nor do we stay at "resorts" ...
Good planning and research will allow you to enjoy what you want, and still keep a nice budget. Planning is the key, but I don't mean reservations ahead of time, I mean planning on where you go and what you see, and careful but realistic in your budget plans too.
