Restrict a users node posting total dependent on a paid subscription role I am interested in how one would restrict a users node posting total dependent on a paid subscription role.

For example, there maybe 3 subscription roles which allow different Node posting for a user dependent on which Role they have chosen on site registration. Using UberCart for example, 3 packages (Low, Mid, High) offer 10,25, 50 respectively to a user. The total posting per month cannot exceed that amount at anyone time in that they can either add/edit/delete an applicable Node (only of their own posting), but not exceed that subscription's total given amount for that role. I would be interested in the best easiest and best approach to this using Rules/Views/UberCart framework. Or possibly knock up a custom table in the backend to tally up the number of said posts per user if that need be the case.

Alternatively, the restriction or limitation of Node  content 'viewing' per subscription role. ie Pay to read more of the said Node content. Which appears nowadays to be an emerging trend for online content access as I see it.

Any comments and ideas greatly appreciated for a learning developer.
In my opinion the best solution would be Ubercart for selling roles to users
 and Node Limit module to set a block on how many nodes can be created by certain roles (in a given period, optionally).

You should set up different roles, one for every different amount of nodes a user can create. Then with Ubercart you have configure a product for every role to be sold.

Then with Node Limit module you can configure the restrictions for every role.