I think you will find the prices comparable. With all three, plus a few offered by insurance companies, you don't call them until you have a problem. With an RV that means your on vacation, your time is important, and suddenly you loose at least a day maybe more because of a breakdown. Your hot (or cold) mad, and probably nothing the road-side-assistance does will be adequate. With that in mind I had AAA, changed after a problem, then had Coach Net, changed after a problem, and now have Good Sam. They did ok with a tire change on the car.
Time will tell.
Happy Trails.