How much should you charge for each video?
Not sure exactly it influences it, but price and how well a video does. Basically the video's length decides what the price range is, then the cheaper it is, the more sales you can possible get, which affects fame and the of the weekly cycle, which in turn opens more events and possible more sales for the next cycle.If the video have decent amount of badges, max it. Don't think I ever seen any complaints about price once I got the hang of filming.
Once you get fame maxed out I think its safe to just go for more expensive prices, however how exactly is the balance income x sales, we don't know, even tho its implied in the formula for the price slider, cheaper + sales, expensive + income.