Selling Courses via Monthly Subscriptions?

Hi @ricsmo! Welcome to Open edX :slight_smile:

Not that I know of, currently. This is a frequently requested feature though, so if you were to develop it, or fund its development, there would definitely be interest & help for it within the community.

You can have a look at the way edX sells professional certificates, for example:

Another option is to handle the registration/enrollment outside of Open edX, and then upload a list of users to enroll in each individual course, similarly to what is described in How to control user enrollment acceptance? - #2 by antoviaque - and potentially automate those steps if there are many courses/students registrations.