Hi Paul,
s2Member allows you to sell access to protected posts/pages on a one-off basis through a feature called Specific Post/Page Access. You can generate a purchase button for the post/page and present it on your site. After a user completes the purchase they will receive an email with an access link to that post/page. The link will only be valid for a specific period of time, depending on what you chose when you generated the purchase button.
s2Member does not have any option to choose the “number of views” per page, but rather allows you to set the length of time the URL should be valid (e.g., 2 hours, 3 days, etc.).
Another thing to keep in mind is that you cannot sell one-time access to the same post/page that you have restricted to a specific membership level. See the note below taken from Dashboard -› s2Member® -› Restriction Options -› Specific Post/Page Access Restrictions:
If you configure s2Member, in such as a way, that a Post/Page requires Membership Level Access, you cannot sell that same Post/Page through Specific Post/Page Access. Doing so, would create a conflict. Customers that purchased Specific Post/Page Access, would be unable to access the Post/Page – without also having a Membership. Not good. So please be careful.
A way around this problem for your scenario would be to create two pages with the same content: one for membership access and another that you sell on a one-off basis for one time access.