Which AI video model to pick
Test on the cheapest model until the photo and the template are right, then re-run the take you like on the most expensive model you are willing to pay for — the cheap models are for iterating and the expensive ones are for finishing.
The families, briefly
Pixverse is the cheap, fast end. Reliable identity, weaker on hands and fast motion. This is where you should be doing your testing.
Kling is the mid-range workhorse and is unusually good at full-body movement, which makes it the first thing to try when a dance template is producing strange limbs.
Seedance holds identity across a long clip better than anything else in its price range — the one to reach for when the face has been drifting.
Veo is the highest fidelity and the highest cost, and it is strongest on scenes and backgrounds rather than on bodies specifically.
The procedure that costs least
Generate a short clip on the cheapest model. You are not judging quality yet — you are checking that the photo works, that the framing is right, and that you like the routine.
Fix the photo if it did not work. This is nearly always cheaper than changing the model, because the most common cause of a bad video is a bad input rather than a weak model.
Only then re-run on a premium model. You are paying the top rate once, for a combination you already know works.
When a Fast variant is the right answer
The Fast variants are not lower quality so much as lower patience. If you are iterating and the wait is what is slowing you down rather than the cost, they are the better trade.