IMHO, on a tight budget, none of the clubs are that good. The lowest cost sites tend to be Corps of Engineers, Forest Service, small town city owned, etc. most of which don't offer club discounts (but some will have senior discounts).
In addition, rather than being a camp host where you just get free camping, consider working at a National Park, where you will get a paycheck and often free camping as well. Do a 3 or 4 month stint, then travel on your own the rest of the year. And while you are working, you still will have plenty of free time. You might decide to do three months in one NP, and three months in another, and the other six months on your own. Working can add to the enjoyment, meeting other people doing the same thing, interacting with the public, learning the ins and outs of NPs, etc.
Some of the small town city campgrounds also introduce you to small town living. I am looking at one right now for an upcoming trip. The city run campground is $20 on season, $15 off season. Meanwhile, the KOA 25 miles away is $59 a night.... And in many of these small town campgrounds, you can walk to restaurants, shops, whatever. And they are not wedged between the interstate highway and main freight train rail line. We traveled through eastern WA recently on US20, seemed like every small town had a city or county owned campground.