What time is the best to join the AMA?

I have been flying park and slope for a couple of years now, since I was in High Desert of California I was able to skirt around the many flying sites (My Back Yard) that didn't require a membership and there was nobody around to hit that would sue me.

I recently moved back home to Washington State, and it is very difficult to find flying sites here, so I am about to Join a Flying club nearby and of course you have to be an AMA member.

What is the best way to do this?