Come on Migflanker. Renting a car in the airport saved you money. Just think. Instead of taking a cab to the off airport rental place, you just saved 50 bucks getting to the place going, and 50 bucks coming back to the airport by taking a cab, plus another say, ten bucks on tips. And to think that by renting a car at the airport, it was ever so much more convenient to drop it in the airport right where you can catch your flight back home. I'd say that your cell phone clip saved you time and convenience and maybe not so much money. Did you really have to drive back to pick up a cell phone or could you really have done without it?
Perhaps a more appropriate Benjamin Franklin quote for your scenario would have been..."HASTE MAKES WASTE."
You got hasty when you took off without thinking about your cell phone. You misplaced your cell phone because you were used to seeing it on your clip, which in turn, caused you layed down your cell phone anywhere. You didn't mention how long it took you to find it when you got back home. Did you find it right away or did you spend a long time looking for it too? Nice Franklin quote but what really went down in the case of the cell phone clip costing you big bucks?