Is jeff bezos still the CEO? i thought someone else took the rains, the former leader of the AWS team.
And my understanding is that they're actually happy to save the customer money in the short-term, because that helps ensure that the customer will have more long-term loyalty.
That's why Amazon has the cost advisor type tools themselves, and why they partner with third parties that also do that sort of thing, etc....
Disclaimer: I work at AWS, but not in any part related to this software. My opinions are my own.