Well I crew and race on some boats as well as belonging to a private club or 20 members. We usually have 3 boats available for use; all 30-32' cruising type boats.
We recently sold one and are in the process of searching for it's replacement. (Was time to upgrade)
We have a "buy in" that I believe is around $4500 and annual dues of $2000/year. You also need to put in 16 hours of maintenance work on the boats. Seasonal prep, cleaning, routine maintenance etc...
For this you can use the boats whenever they are available by going online and reserving the boat. We do have limitations on the number of days you can have a boat reserved (no blocking out every weekend for the season!) but there is almost always a boat available. And if you're off during the week like I was for many years it's GREAT! Only trouble is no singlehanding allowed. But to get access to a decent cruising boat at minimal cost is pretty nice.
That said I'm looking at getting my own boat b/c I want more control over how it's set up, want to singlehand, and don't want to share!
Oh, and when you sell to get out you get whatever the share price is then.
But it's still a good deal.