The "estimated cost" or "expected cost" of an Airhitchable hop across water is defined as the amount Airhitchers can expect to pay, based on what people have had to pay across the entire cumulative experience of the entire history of Airhitching back to 1969 and adjusted for inflation, under ORDINARY CIRCUMSTANCES, that is, unless something very BIZARRE AND EXTRAORDINARY occurs which impacts cost. Of course, even if something out of the ordinary does occur, you can always just not pay the cost, and elect to take some other more ordinary flight! How do we define "extraordinary"? Something that we have no way of predicting, and that happens "once in a blue moon" (say, less than 0.1% of the time, i.e., 0.1% of the time Airhitchers try to get on airplanes).

Why can't I know EXACT costs? Why can you only tell me "expected" or "estimated" costs?