The cost of the systems is almost irrelevant. The time of qualified people is far more expensive. Sot it's not just the elasticity. You have to look everything from the time perspective as well. What additional knowledge will I need? Will I need to learn load balancers, how to make them highly available? will I have to learn about SSL certificates and termination? Will I need to learn how to implement and operate a secure and highly available DNS service? How much is your time worth?
Our hosting costs are a fraction of a single worker's salary. Whether AWS is more expensive is essentially irrelevant. OP argues that it was not doing the job for them which is an entirely different issue.
Don't forget the quality of the work. Frankly, if I'm administering servers I'm not going to do as good a job of it as someone whose whole job is that and I'm not going to do as good a job as Azure or AWS or whoever else either. Platform as a service is the way to go.
Because if your sysadmins are all moonlighting developers having them not develop stuff to do subpar system work is more expensive than just paying the cloud premium.
