AI video forms often make the expensive decision feel like a cheap one. A creator chooses a model, duration, resolution, and audio mode, but the interface hides the consequence until after they press Generate.
That is more than a pricing problem. It is a product-state problem: the cost is derived from the same controls that define the output, so it should update in the same interaction loop.
This post explains the pattern I used while building an image-to-video workflow around Grok Imagine 1.5 Preview.
1. Make cost a derived field, not a checkout surprise
For the current Grok workflow, the supported duration is 1–15 seconds. The UI offers 480p and 720p. In this implementation, 480p is charged at 1.6 credits per second and 720p at 3 credits per second, rounded up to a whole credit.
