That's a LOT of money to spend up front on a gamble that something which has never happened before occurs with so little notice that you wouldn't be able migrate away first. It's hard to see anyone but the major players having enough economy of scale to see positive returns on that investment, much less having enough budget room to where that makes sense rather than spending the same amount of money on something which users actually see.
That gets to the other reason why this is so unlikely: raising prices in a predatory manner would be a loud message to every AWS customer to find alternatives. Since AWS generates something like 7-8 billion dollars a year that's an enormous amount of money to risk — far greater than any short-term return they'd see.
