There is a scale between prise-sensitivity and risk-averseness, from my point of reference large companies are much more risk-averse than they are price sensitive. Of course this will vary, CTOs exist in all sort of different environments.

Price is not the reason people chose AWS. Some companies use Azure. The current startup at $WORK uses yet another smaller Cloud. And yet AWS sill has the clear lead in market share. That's because price is far from the only factor, and not even the main factor.