> I was an on-prem maxi (if thats a thing) for a long time. I've run clusters that costed more than $5M, but these days I am a changed man.

I have had a similar transformation. I still host non-critical services on-prem. They are exceptionally cheap to run. Everything else, I host it on Hetzner.

In addition to those sorts of non-first-hardware-purchase costs, the person writing the check needs to think long and hard about how bad an outage would be, and how much money it makes sense to budget simply to "avoiding outages." And the more important it is not to have any downtime, the more it's gonna cost to build up some sort of substitute for cross-datacenter cloud functionality. (You are also likely not going to be as good at either managing and configuring those networks, or hiring people to do so, as AWS, either.)