Selling access to Access-Restricted Pages.

I'm wondering if it possible to set up access-restricted pages that can be unlocked via a "currency" of some sort. For example, a user would be able to purchase 10 credits with say $x.xx; each credit would then be consumed to gain access to a page and only that page.

This isn't a subscription as the user is purchasing access to an individual page. I am wondering if it is possible, and if so how, to set up an on-site currency system (purchasable through USD) which can be consumed to gain access to a single page.