Perhaps you didn't see his decimal point. He's saying half a cent, not fifty cents.
I saw it. It's still wrong. What we get is .0045, roughly, which is half a cent more or less (less, as I don't think we've gone over a half penny more than a couple of times). Those two zeroes make a difference.
As to shadcallister's comment, the reason different books with the same word count come out different for KENPC is that Amazon is almost certainly counting characters, which includes all spaces and enters. What they consider a page concerns what they give you for a page count on the book's page, but seems to have little to do with what used to be considered the words on a physical page.
Believe me, there were a lot of us on a certain group who were trying to figure out how the KENPC was figured, to see if we could maybe fudge a page or few out of a book. It came down to making more dollars out of the same book, without going too far over any perceived limits Amazon may have had. So, people fiddled with line spacing, font size, margins, and so on. At first, you could increase your KENPC by going a little larger on the font, or doing 1.5 spacing instead of single, or whatever. Amazon soon rebooted and stopped allowing that, or so they said. I've read there are some manipulating the CSS code to get past it still, but I'm not sure if it works, or ever did.
What was left was basically having more enter keys hit, i.e., shorter paragraphs, because they're counting characters with some sort of formula, and not just words per "page". At any rate, you still make more money by writing longer books.