A three-stage video funnel: Grok, MiniMax H3, Seedance 2.5 costs

Twenty ideas screened on grok-imagine-video-1.5 ($0.0625 each), five survivors on minimax-h3 at 768p ($0.375 each) and one final on seedance-2.5 at 1080p ($7.11) cost $10.23 on Sume, all as 5-second clips. The last clip is 69% of the total, so the funnel's job is to make sure you only pay for it once.

Stage by stage

Rules that keep it cheap

• Grok Imagine Video 1.5 is image-to-video only, so stage one needs a still for each idea; use the same still as the first frame at the later stages if the model accepts it.
• Same duration at every stage, so prices compare cleanly.
• Cut by a written yes or no per clip before moving up a stage.
• Re-use the winning prompt verbatim on the next model; change only model and resolution.
• Tag each job with a human-readable Idempotency-Key such as funnel-3-grok.

Skipping stage two

Going straight from Grok to the Seedance 2.5 final saves $1.88, but it removes your only mid-price check. Keep it when the final model's behavior on your subject is the main uncertainty.

Scaling the shape

Scaling to 100 ideas, 20 shortlisted and 4 finals, still at 5 seconds, costs $42.18. The final stage is still the largest line; the funnel exists to keep it small.

Sume reserves the full price at submit, so the number in the table is also the amount that must be free in the balance when you send the request. If it is not, the call fails with 402 insufficient_credits before any provider work starts.