> The bigger cost is what will happen to your business when you're hard-down for a week because all your SQL servers are down, and you don't have spares, and it will take a week to ship new servers and get them racked. Even if you think you could do that very fast, there is no guarantee. I've seen Murphy's Law laugh in the face of assumptions and expectations too many times.

Lets ignore the loaded, cherry picked situation of no redundancy, no spares, and no warranty service. Because this is all magically hard since cloud providers appeared even though many of us did this, and have done this for years....

There is nothing stopping an on-prem user from renting a replacement from a cloud provider while waiting for hardware to show up. That's a good logical use case for the cloud we can all agree upon.

Next, your cost comparison isn't very accurate. One is isolated dedicated hardware, the other is shared. Junk fees such as egress, IPs, charges for access metal instances, IOPS provisioning for a database, etc will infest the AWS side. The performance of SAN vs local SSD is night and day for a database.

Finally, I can acquire that level of performance hardware much cheaper if I wanted to, order of magnitude is plausible and depends more on where it's located, colo costs, etc.