Several years ago I inquired. It was something like $1000 fee to join plus $500 a year. I'm not sure what it is now.
They have had to allow people outside to join because parts of the subdivision have gotten the covenants changed to allow homeowners to install pools.
I think that at some point last year they either reduced or dropped the registration fee, on order to get more people to join. You may want to give them a call again to inquire. Another issue that they're having is that not all homeowners are required to join (it's an extra fee on top of the HOA dues), so they've seen memberships decline pretty steadily. Also, if you're planning to join this late in the summer, see if they'll cut you a deal. Maybe do a proration or something.