> Stay well-informed about the world each week with clear and concise summaries of important news ...
That sounds like an exactly perfect fit for Substack. We've seen that if you have a committed newsletter following (look at open rates and reader comments) that loves it, up to 10% of your list might pay pretty quickly if you just asked them. Depending how they think they could price it could be worth over $1000 month to start. Of course, this depends on the audience etc.
If they want to do it, it's a simple as signing up, connecting Stripe, and importing the existing list. They can send out a 'free' post saying that the newsletter is going paid, and it will go to that list, and come baked with calls to action to subscribe and stuff.
We've done a couple of these now and would be happy to help. Feel free to point them to 'chris' or 'hamish' at substack.com