Sorry for not being clear.
We want to be able to charge users on a rolling monthly basis. Different levels of subscription would allow us to charge more. If we use the examples in the link you posted, level 1 plan would mean that the user could post 5 lots of Places, level 2 plan would mean the user could post 10 lots of Places and one event, and level 3 plan would allow the user to do 10 Places, two events and one business.
Does that make more sense? From what I can see when trying to set up a plan, it looks like you can only limit categories of a post type.