Nano Banana 2.1: fal's $0.040 at 1K vs Sume's tier prices

fal's Nano Banana 2.1 page, read 2026-10-13, shows $0.040 per image at 1K, $0.059 at 2K and $0.134 at 4K for a short prompt with medium thinking, billed by token. Sume's repo price table carries list prices of $0.06 at 0.5K, $0.08 at 1K, $0.12 at 2K and $0.16 at 4K, so Sume bills $0.0750, $0.1000, $0.1500 and $0.2000 per image. The Sume table is dated (a 2026-10-06 note in the code), and the fal page is more recent: the live catalog decides what you pay.

Per 100 images

The two columns are not the same quantity: the fal figures are what the vendor page shows today; the Sume figures are the repo list times 1.25. They are shown together so you can see the size of the gap, not to claim either is wrong.

How to check before a big run

Call GET /v1/images/models and read the Nano Banana 2.1 row's pricing; the image docs say billable_margin is 1.25 on every row and the submit envelope returns billable_amount_usd_micros. Run one image per tier, compare usage.cost with the table, then scale the batch (image docs).