Cheapest Seedance 2.5 test clip: 4 s at 480p is $1.08

The cheapest Seedance 2.5 job on Sume is a 4 s clip at 480p, which costs $1.08. The same 4 s is $2.31 at 720p and $5.69 at 1080p. Seedance 2.5 has a 4 s floor, so for sub-dollar tests use Seedance 2.0 Mini ($0.44 for 5 s at 480p) or Wan 3.0 (2 s at 480p is $0.13).

Why the floor is 4 seconds

SEEDANCE_MIN_DURATION_SECONDS in the pricing tables is 4 for every Seedance family, and the 2.5 maximum is 30. A request for 3 s on seedance-2.5 returns a 400 rather than being rounded up. Duration must be a whole number.

Minimum prices

Tokens for 4 s are 40,176 at 480p (864x496), 86,400 at 720p and 194,400 at 1080p, all at 16:9. The list rate is $0.0214 per 1,000 tokens, or $0.0234 at 1080p. Sume multiplies by 1.25 and rounds up.

A test routine that stays cheap

Write the shot as one sentence of action and test the prompt, the references and the framing at the floor length. Do it at 480p and never at 1080p. Check three things: whether the references loaded, whether the subject stays on model, and whether the camera does what you asked.

Once those three pass, extend. A 10 s 720p Seedance 2.5 clip is $5.78. Remember there is no seed, so the final render is a new take, and the test only proves the prompt.

The request

Use the catalog id and set both duration and resolution. A missing resolution takes the model default, which may be above the floor tier.

curl -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"seedance-2.5","prompt":"A cat leaps onto a kitchen counter, handheld camera","duration":4,"resolution":"480p","aspect_ratio":"9:16"}'

When 2.5 is worth the test

Test on 2.5 itself when the thing you are checking is specific to it: a 30 s duration, a reference video, an audio reference or a 21:9 frame. Test on Mini or Wan when you are checking only the prompt and subject. A test that uses a different model tells you about that model.

A dollar per test clip is cheap against a $42.65 30 s 1080p render. Ten tests plus one final is $10.80 plus $42.65.