The costs are definitely a huge consideration and need to be optimized. A few years back we ran a POC of Open Shift in AWS that seemed to idle at like $3k/mo with barely anything running at all. That was a bad experiment. I could compare that to our new VMWare bill, which more than doubled this year following the Broadcom acquisition.
The products in AWS simplify costs into an opex model unlike anything that exists on prem and eliminate costly and time consuming hardware replacements. We just put in new load balancers recently because our previous ones were going EoL. They were a special model that ran us a about a half-mil for a few HA pairs including the pro services for installation assistance. How long will it take us to hit that amount using ALBs in AWS? What is the cost of the months that it took us to select the hardware, order, wait 90 days for delivery, rack-power-connect, configure with pro services, load hundreds of certs, gather testers, and run cutover meetings? What about the time spent patching for vulnerabilities? In 5-7 years it’ll be the same thing all over again.
Now think about having to do all of the above for routers, switches, firewalls, VM infra, storage, HVAC, carrier circuits, power, fire suppression.