I remember when we first had someone mow our lawn a neighbor made a point to tell us that it only took the service five minutes to finish the whole lawn. We thought that was great. The neighbor thought the lawn company was ripping us off.
The man who built our wall told us the story of a job he did planting a number of trees. The woman who hired him refused to pay him the agreed-on amount because he took only forty-five minutes to do it, instead of the two hours she felt it should have taken him.
When I got my hair cut at a fancy West County salon, my stylist pointed out an older lady who was having her hair done twice in one session. The lady insisted the hairdresser wash it, roll it, dry it, spray it, and then start all over again with a wash, roll, etc. She had fine hair, and she felt she should get as much of her stylist's time as someone with long hair.
Is there a rule that governs these things? When do we pay for time and when do we pay for a result?