I received one of those type calls a year or two ago. Initially I said yes as I would attend cause it sounded OK. Then when I got off the phone I did a google search on the property and the business, saw a lot of complaints. Basically, you are buying a lifetime membership to this group of campgrounds. Besides the initial fee, you also have to pay an annual maintenance fee for as long as you "own" your membership, which you can't just stop - you have to sell. I decided it wasn't my cup of tea so called them back and cancelled.
Don