[hwbehrens]

It also ignores that if you booked a trip to a place, you likely did so because you want to go to that place. Thus, if you were forced to cancel your trip due to a conflict, it is implicitly more likely that you would book a trip there again in the future - a rain check, essentially.

If the question was "Which of these trips would you like to pay for twice?", then it's immediately obvious that the cheaper trip should be cancelled.