$1 – average 45 calls per day, covers ~45% of users (Google: $.15 / minimum of $.52 to Relay)

$2 – average 100 API calls per day, covers ~80% of users (Google: $.30 / minimum of $.97 to Relay)

$3 – average 200 API calls per day, covers ~95% of users (Google: $.45 / minimum of $1.09 to Relay)

$5 – unlimited API calls per day, covers ~99.8% of users profitably (i will likely carry a small loss on the remaining .2% of users but that should be negligible if enough users sign up).

https://www.theverge.com/2023/8/17/23836528/reddit-relay-android-app-subscriptions-potential-price