Runway Seedance 2 at 40 credits per second vs Sume at 1080p

Runway's API pricing page lists seedance2 at 36 credits per second at 480p and 720p, 40 at 1080p and 150 at 4K. At $0.01 a credit a 10-second clip is $3.60, $4.00 or $15.00. Sume's seedance-2 reserves the provider list price times 1.25 and offers 480p, 720p and 1080p, with no 4K: a 10-second 16:9 clip is $1.76, $3.78 and $8.51 before the agent fee.

Runway facts are from its pricing page, read 2026-10-01. Sume facts are from the video docs and its pricing code. The sums are arithmetic on those numbers, not a quality comparison.

What does a 10-second Seedance 2 clip cost on each?

Runway prices 480p and 720p the same. Sume prices each resolution separately and adds a 5.5% agent fee by default.

Why is Sume's 1080p step so large?

Sume reserves list price times 1.25, and the provider's list price grows with pixels: Sume's per-second figure goes from about $0.18 at 480p to $0.38 at 720p and $0.85 at 1080p. Runway's page shows a flatter 36-to-40 step across the same sizes. Draft at a lower resolution when the final frame size is not yet decided.

What else does Seedance 2 on Sume accept?

seedance-2 takes 4 to 15 seconds. The router docs describe seedance-2 as offering 1080p, which the 2.x mini id does not mention. See Seedance 2.0 resolution pixels for sizes, and cheapest Seedance 2.0 API for the cheaper ids.

How do I confirm the price before I submit?

GET /v1/catalog lists each model's rate and the agent fee. The reserve is held on submit; when a result is ready, usage.cost shows the Sume billable amount. A balance below the reserve returns 402 insufficient_credits.