Usually the real answer is that it isn't actually $50k for a trash can. In something like an airplane, there's a whole bunch of costs that are overhead on the plane itself without being attached to any particular part (delivery, integrated testing, R&D, whatever). The accounting convention is that the overhead gets spread out amongst the individual items. The side effect of this convention is that if you view a line item without context, you get something utterly nonsensical.

It's absolutely possible to apply some level of basic human reason and common sense to such situations. A different accounting convention is probably in order.