I've been on a prepaid plan for years, and I never have to add more than $100 USD each year to carry my existing balance forward.

This is a no-data plan and any day I use the phone I get 24 hours of unlimited talk and text and my balance gets charged $2. So if I used it every day it would cost me $730/year for non-leap years, about $61/month.

As long as I don't exceed 50 days/year I just add another $100 annually. I'm a light phone user so I still have a balance somewhat over $200 right now.

Any day that I get a legit call or a spam call that gets past the filter or send a text it costs $2. But that gives me 24 hours to make social calls and texts to family and friends. I can only think of two years when I had to add another $100 and I could probably have just added $50 or something.