Payment management system for Trello Power Ups that you publish

I'm in the process of turning a personal Trello Power Up into a public one so that other people can use it on their own Trello boards. I was surprised to learn that Trello has no payment management solution for Power Up developers. I haven't found any solutions elsewhere. It looks like I will have to implement my own. I think this will take more time to build than the Power Up itself!

By "payment management system", all I mean is a system that will:

1. Allow users to buy subscriptions for premium tiers of the Power Up.
2. Store this subscription data in a database that my Power Up can read from so that it can know which features to surface to which user.

Would you use something like this?