These AI video systems will need huge amounts of random videos showing things like leafs rustling in the wind, car driving, etc. so you don't even need to put in 10 hours of effort to create a 10 minute video, you can just grab your camera and go for a walk and publish that as it is, and it will be valuable training material.
$3 per minute would be a pretty high price to pay for "man walks outside" video.