I really wish Stripe would just make something like this. Just the bare minimum necessary to host Checkout for products entered in your Stripe dashboard. I wonder if they can’t due to some onerous clause in their agreement with Shopify.
Definitely check them out - they're great. Easyful is just a fulfillment layer that plugs into Stripe payment links for emailing customers your content when they buy something.
Have you done a write it up English for how that works? Does stripe send emails and you just have the emails contain the content as attachments or straight text?
When you start competing with your customers, it typically doesn't end well.