Gaggle Mail (https://gaggle.email) has a free plan and it's cheapest paid plan is $100 per year. It's popular with family groups doing what you describe.
I’ve been running Gaggle Mail (https://gaggle.email) for over 10 years, and mailing lists are still very popular in certain circles. They’re especially valued for long-form discussions — legal groups, professional associations, HOAs, and similar communities still rely on them because they’re simple, reliable, and easy to archive.