I suppose also that you shouldn't forget that someone who provides you with a service is entitled to make a margin. Nobody is in business just to break-even. Having said that, when you do your own sums, and then look at the "same holiday" with various operators, it is astonishing how much some are adding on.
Have you ever talked to fellow holidaymakers who are actually impressed with the rather high price they paid? I've met them many a time, and I suppose you can't blame the operators for selling like that if they can.