Grok Imagine UI update is coming soon: before you generate a long video like in Director mode, you'll see how many images and videos will be created so you can adjust the count or decline before it starts.
Slightly to be expected because creating a lengthier video will generate multiple images and video shots. Subsequent edits shouldn't be as costly, but in general this should get cheaper overtime 🤞
A fix for the UX is going out soon, it will tell you how many images and video shots will be generated so you can adjust or decline.