membership

Here's what I would like to do. Please tell me if it's possible with the membership plugin and if so, how to implement it.

This is the scenario: I sign up a new user (A) and enable that user to have user sites (A1, A2, A3, etc.) under them. I know this can be enabled. My question is: can I (super admin) charge a monthly membership fee to all the new users (A1, A2, A3, etc.)? Would I have to install the membership plugin on the top user (A)? I also want to make the user (A) site free, but still a member.

Thanks, Joe.