I'd add that it isn't just rates, it is also the no turn away policy that makes hiker biker sights important. For those not familiar with hiker biker sights they are usually either a group site of a regular camp site that you share with other hiker or cyclists.

On the east coast, assuming decent rates, it would be wonderful if the hiker biker system was implemented. For much of the middle of the country it is a lot less of an issue since it is usually pretty easy to find a place to camp for free in plain sight. Small town folks there seem to be a lot more laid back about a cyclist pitching a tent in their town park or sleeping under a picnic pavilion roof. In a lot of the west and the plains states I find I camp for free much more often than not.