One practice I've found useful, that is more general, was to issue weekly reports breaking down the cost of each activity. That is, I'd solicit a ~5-10 line breakdown from everyone in my team of how they spent their time that week, and I'd apply average costs for their function and tally it up.

So we might see posts like $2k for a planning meeting show up on the report, and suddenly people started paying attention to what time was spent on - both for meetings and otherwise.

And making arguments like the one in your example. It also meant being able to make actual estimates over whether pursuing a certain optimization would be worth it vs. buying more hardware.

Amazingly each place I've done this at, they were initially confused why I wanted to do this, as apparently it was weird and unusual to have engineering issue such breakdowns

Wonder how much "weekly report compilation" would cost :-)