Luma uni-1 pricing: +$0.0030 per reference vs Sume pricing lines

On Luma, uni-1 text-to-image is $0.0404, an image edit is $0.0434, and each extra reference image adds $0.0030, so nine references cost $0.0674. For Sume, read the pricing line from GET /v1/images/models: the docs say that line is the amount charged to your wallet.

Luma prices are from its Pricing page; Sume facts are from Image models, read 2026-10-01.

What does uni-1 cost per image?

How do I budget an N-reference request?

Take the 1-reference price and add $0.0030 for each reference after the first, as the page states. Eight references on uni-1 then come to $0.0644, the page's own figure. Every Luma request outputs at 2048 pixels, so there is no size term to add.

How does Sume show the price?

Each endpoint carries a pricing line, and the docs say Sume's margin is already applied, so cost_usd × n is what you pay. Billing is all-or-nothing: a completed image is billed in full, and a failed or cancelled one is not billed.

The Image API doc lists input_references as a single parameter and says nothing about a per-reference step, so read the line for the model you call and compare a request with and without references.

What should I check before comparing the two?

Compare the same job: output size, number of references and number of images. Luma's numbers are for 2K output; a Sume model may default to another tier. For a worked example of reading Sume lines, see OpenRouter image pricing lines versus Sume endpoints.