We use Passport America - you get 50% off camping fees. There are restrictions that each campground has such as only good 1 night, only good Mon - Thurs, but there are also plenty that will allow you to stay longer. There are 1900 parks and prices can range from $8 night on up to 1/2 off at some pretty nice resorts. We usually figure $25 night at the most and usually can find a Corp of Engineer, Forestry Park , County Park, City Park or a Passport park to stay at. We have never paid more than $35 night in 4 years.