But according to IMDB, even "Brokeback Mountain", most of which was two dudes sitting round a campfire not even saying all that much, cost $44 million to make. Clearly some of that went on overpricing by suppliers (and actors?) who knew their customers were loaded -- overpricing, in other words
I don't see how it's any different to Football (eugh!) where blokes who would most likely be binmen, carpet fitters or insurance salesmen in another life can be paid £100k a week to chase after a ball. These industries are all self perpetuating with salaries that increase year on year like Moore's law.
With regards to technology and equipment, costs really can get out of hand very quickly. Film stock alone can be ludicrously expensive, add to that the hire cost of decent cameras, lighting and grip equipment.
Also, the film and TV industry in the US is massively unionised which means they really do pay people large sums of money to just sit on their asses all day doing nothing.