>I'm always bugged by whiners complaining that they bought a return flight from New York to London for 399$ and then complain that they can't change it, because they just don't seem to grasp the concept of non-refundable. If you want refundable, that can be had. For 4x the price.

giving the high volume (and thus in particular high statistical predictability available to airlines), the huge spread between refundable and non-refundable strongly suggests that there is something out of whack here.