I love it when customers don't live in the real world when niggling about expense costs....
My favourite was an airport operator who complained that we were charging them £65 per night for the hotel at their airports... but when asked couldn't actually find one for under about £80
Or who complained about travel costs - when we were using the actual (standard) train fares with no mark up... Customer comment on that occasion "We aren't allowed to travel first class anymore"