To be honest, I would use package for this kind of situation. For example, in Ruby on Rails one could simply create gem and add it to two different repositories. Additional thing is that you have a version control. Nice work anyway!
There is no such thing as obscene pricing. If customers are buying subscriptions then the pricing is right and product is needed. If author of the course can make such a thing in 2 nights - cool. But she should realize that not everyone has skills and time to do that. It is easy to judge.
In my experience, stripe and shopify are not that easy. To use stripe you need to go through the process of making an account and its verification. Sometimes it is taking days to set it up. Shopify is a slightly better solution. But still, this is a huge application with a lot of painful processes. I need something, that offers set up in minutes, but I haven't found any solution yet.
