I was a GoodSam member for a while many years ago. Then I realized that every time I wanted to stop, there was no GS park nearby. I know of one here, and one in Great Falls. I don't patronize either place. I allowed it to expire.
I joined KOA for our trip to Ringgold, GA and back. the discounts more than paid for the membership. Again, there is one here, and one in Great Falls. I don't patronize either place. That membership has also lapsed.
The bottom line is, IF you can or will use the benefits, join a club. If you will not use the benefits enough to get your membership back, IMO don't bother to join, it is a waste of money.
Note: When in Great Falls, we normally stay in the AFB FamCamp. The rest of the time we are in Forest Service campgrounds.