New user - seeking clarification on per page access restriction

I hope someone will take pity on me - I have been though WishList and s2Member - now I have found the WPMU plugins which look amazing. I have installed Membership and am reading the documentation and this forum, but I am unclear if Membership will do what I need, and if so how. Having spent weeks going down rabbit holes I thought I'd see if the community could help...

I am setting up a website that will sell music lessons - an embedded video on a page for each lesson. So I want someone to be able to come to the site and register, set up a profile if they wish... and then purchase a lesson though Paypal. Upon purchasing the lesson (access to that page) they would receive access to the page. Then hopefully they will buy a second lesson/page... etc...

So how can I do this with levels? I can't have a level for each lesson, because people will buy more than one lesson... I can't have levels for the infinite number of possible lessons (e.g 1,2 & 6...)

WIth s2Member you can set up restrictions on a per-page basis - just what I need to do. But the access is granted to an IP address (i.e., don't try to open your lesson at Starbucks....)

Any pointers would be sooo appreciated.