At work, people keep complaining about our costs and coming up with spreadsheets showing how much money we would save with our own hardware.

They never add the engineering costs. When they do, they forget to include the ongoing maintenance. Or the new SMEs that need to be hired (and on call). Or even the opportunity cost of doing a multi-year migration to arrive at the exact spot they already are today.

All that money, and noone is looking into optimizing our systems to shrink the bill...