Easy project, using mostly video transitions.
Biggest question depends on how many images you need. A content creator on fact videos, the more images the better, however this can become time consuming for the video editor who isn't provided with the images.
Also, I'm sure you want some return on this as it would be going to Youtube, earning revenue off Adsense. So, the lower your cost, the better you are able to profit.
By the way, these videos do not have to be super complicated or fancy. Most people listen to the video in background.