Is this right:
First 5 pages – Administrators ONLY, NO subscribers
Sixth page – Subscriber ONLY, NO Administrator ?
If this is correct than you only have to add the capability type as ‘administrator’ when creating the first 5, and ‘subscriber’ for creating the sixth. That should work. Or add a new capability for admin, use it while adding the first 5, and a new capability for subscriber, use it while adding the sixth.