Yeah, I think you have to get further into the sign up process to see all the options. And some of the higher plans (beyond 4 or 5 at a time) might not even show up there, and in your account options once you have an account.
That's the way it was when I signed up, but that's been a few years. But the plans Jim Beam posted are 100% right as that's what shows up in the options now on the screen to change my plan.