It will take 100 hours to consume 1 KWh at 10 W. So at, say, 10 cents per KWh, this amounts to like ten dollars per year of 24/365 operation or to $800 for a full human life.

This is something that needs to be taken into account if one is planning to buy a new machine to reduce power draw by like 5W.

This is not taking into account the footprint of producing that extra machine earlier than it would need to be produced.