They don't change vastly enough for his earlier claim to be true. He wasn't even quoting the actual amazon price, just one of the third party dealers that go through amazon, and the most expensive of those third party dealers at that.
That's fair, I'm ok with just expecting my 3% discount on the site (credit card transaction fee eliminated).
I agree that trying to be more aggressive on price competition doesn't really seem valid or possible since I don't understand where the money would be coming from.