I agree with the above - doesn't seem like much of a "club" based on what you describe, seems more like an FBO trying to get more money out of the renters.
A more typical club would be an equity-based club, where when you buy in, you actually own a share of the airplane(s). Of course, these cost more to buy into, like in the thousands. But with ownership, now you can sell your share (depending on club rules) when you leave. Typically an advantage is fewer people using the airplanes, less wear and tear, nicer planes, hopefully the others treat it like they own it (as in, treat it nicer than renters). Downside is when there is maintenance, the bill is split among the owners (you).
A non-equity club like the one you're describing would only have any benefit if it resulted in lower hourly rates for club members, or some other reason to pay a monthly fee to belong. I've seen clubs where the rental rate is discounted say 10% for club members, so if you fly above a certain number of hours a month, it's a good deal. Otherwise not.
It doesn't seem like this "club" is giving you much benefit.