> A large part of the different views on this topic are due to the way people estimate the amount of saved effort and money because you're pushing some admin duties to the cloud provider instead of doing this yourself. And people come to vastly different conclusions on this aspect

This applies only if you had an extra customer that pays the difference. Basically argument only holds if you can’t take more customers because upkeeping the infrastructure takes too much time or you need to hire extra person which takes more money than AWS bill difference.