Which price point is the most profitable for selling an ebook?

Thanks for taking the time to create a post and share the information. I imagine that many people who publish their own books and informational products online struggle from the problem of knowing how much to charge for their products. I have seen various examples of people who sell mini-reports for $1 or $2 and do very well. These are reports that are only a few pages long. The typical book online ranges into the tens of pages if not hundreds. A small report can be created in a day where as the book requires several days to write. The challenge is finding that price point that is the most profitable while also selling the largest number of copies possible.