Saving starts with fewer unsuccessful attempts, not the lowest headline rate. A first test only needs to establish an idea, movement or composition. Choose final size and longer duration after a useful draft.
It depends on the task and settings. Even a lower video-reference rate can cost more once input time is included.
Check the selected model's table: different modes may have the same price. The full pre-request total matters.
Do not assume so. A new request is a separate generation; check its price before confirming.