Cost per kept second of a 30-second Seedance 2.5 clip, 1 to 4 takes

A 30-second Seedance 2.5 clip costs about $17.33 at 720p and $8.06 at 480p on Sume, but you pay for every take you generate, not only the one you keep. If you keep one take out of three at 720p, the cost per kept second is about $1.73 instead of $0.58. Plan the budget around takes per keeper, not around the single-clip price.

How Sume prices a take

Sume bills Seedance by output tokens: width x height x seconds x 24 / 1024, at the Seedance 2.5 list rate, times a 1.25 margin. The Video Router docs state that Sume bills list x 1.25 on every model. Every completed take is billed whether or not you use it. Failed jobs are a separate case covered in what a failed job costs.

Cost per kept second

Divide the total spend by the 30 seconds you keep. The table assumes you keep exactly one 30-second clip and generated the stated number of takes, each at the same settings.

Ways to lower the takes per keeper

Test the idea in cheap probes before the 30-second run. A 4-second 480p take is about $1.07, so you can try five different openings for the price of less than one 30-second 720p clip. The prompt and references that survive probes are the ones worth the long run.

Cut instead of regenerating when only the ending is wrong. The video trim endpoint returns a new MP4 for a chosen range at $0.02 per job, which is far cheaper than another full take.

Set a ceiling before you start

Decide how many takes you will pay for before accepting the best one, and stop there. Three takes at 720p is $52.00; if that is above the value of the clip, drop to 480p for exploration or shorten the clip. Sume reserves the estimated cost at submit, and a request that cannot be reserved fails with 402 insufficient_credits per the generation admission docs, so a low wallet stops a runaway loop but does not replace your own limit.