Ultimate plan user here and I appreciate the discussion so far.
Here's an idea: two buckets for AI credits: (1) monthly and (2) extra.
The monthly bucket is included in your plan, and the number of credits is based on your plan level.
The monthly bucket renews each month but credits from the monthly bucket DO NOT roll over. Whatever you don't use each month, you lose.
Credits for the extra bucket can be purhased at any time, and you DO NOT lose these credits each month. They stay until you use them. (Or you lose them eventually if your account becomes inactive for a year, let's say)
All API calls would draw from the monthly bucket first, and then the extra bucket.
All credits would be priced sustainably to ensure Kagi's longevity. Potentially a higher margin on monthly plan credits than extra credits, but this is up to the Kagi finance and product teams.
Essentially this is just the existing plan with the addition of the extra bucket instead of having to renew early when you run out of credits.
Coincidentally, this is the same plan my metro card uses!
Thoughts?