Here’s a “working” solution (for developers at least) from another post: "Pay what you want" price - #8 by kevinmiguet
and other requests for this feature are in these threads:
- Migrating from Patreon to Ghost and looking for "Pay what you want" Tier pricing
- Any plans to allow members to pay what they want?
- Newbie Questions - Importing a Weebly Blog / Pay What you want subscriptions
- Other Amount Subscription
- Can you make paid subscriptions optional and flexible?
- Allow members to pay more than minimum