GPT Image 2.5 on fal runs $0.00402 to $0.40026 per image: on Sume

The fal page for ChatGPT Image 2.5 Flare (read 2026-10-08) gives a cost range of $0.00402 for a 1024 by 768 image at low quality to $0.40026 for 3840 by 2160 at max. Multiplied by the 1.25 that Sume's price book applies to provider list, the same two images come to about $0.0050 and $0.5003. That is a 100-fold spread on one model, and it is why Sume's catalog line for this row is only a display rate.

The spread comes from token billing. The Sume docs give the Fal rates behind both ChatGPT Image 2.5 ids, Flare and Sunburst: $30 per million output image tokens, $8 per million input image tokens and $5 per million input text tokens.

Two ends and the middle

The docs also give the 1024 by 1024 output prices for the two top tiers: $0.09366 at xhigh and $0.21072 at max, before input tokens and Sume pricing. Fal rounds the total up to $0.0001. Multiplying those by 1.25 gives the billed figures in the table, still before input tokens.

Two traps in the settings

Leaving quality out is not the same as auto. If you omit it Sume sends high; auto reserves the max price for the admission hold, and size auto or a named preset without a verified mapping reserves the upper bound of output tokens. Send an explicit quality and an explicit size when you plan a batch.

Custom sizes have rules: both edges multiples of 16, longest edge at most 3840, aspect ratio at most 3:1, and 655,360 to 8,294,400 pixels. 3840 by 2160 is exactly the pixel cap; 1024 by 768 is just above the floor.

What to do with the range

Treat the low corner as a draft price and the high corner as a deliverable price. Keep the draft at low quality and a small size, and re-run only the keepers at the top. Read usage.cost on every response and total it, because on this row the prompt length and any reference images move the charge, and the endpoint's pricing line is the display rate for one high-quality 1024 image.

For a batch plan, write down three numbers before you start: the draft price, the final price and the share of drafts you expect to keep. Ten keepers out of a hundred at the draft and final prices above is a very different bill from a hundred finals. Then check the first few usage.cost values against your estimate and stop if they are far apart.