My wife's son had the "platinum membership", which is good forever (so he gets it back when we kick the bucket). I think it cost a few thousand, but less than 5. They have other packages I don't know about. They also sell leases, for people that want to live there permanently, for either camp sites or park models. A number of retired folks do live there permanently. The platinum membership also allows us to use the Styx River resort in RobertsDale, AL (http://www.styxriverresort.net/)
. We haven't tried it yet.
One thing -- it may not the best place during the summer months, when school is out. Crowded, and lots of kids. Really nice when the kids are in school, though. And open all year.