How to Charge $546 for Six Liters of Saltwater

as the tale of the humble IV bag shows all too clearly, it is secrecy that helps keep prices high: hidden in the underbrush of transactions among multiple buyers and sellers, and in the hieroglyphics of hospital bills.
At every step from manufacturer to patient, there are confidential deals among the major players, including drug companies, purchasing organizations and distributors, and insurers. These deals so obscure prices and profits that even participants cannot say what the simplest component of care actually costs, let alone what it should cost.

The term is information asymmetry. And it is one of the reasons why health care in the US is so damn costly and everyone claims that they are not the ones making money on health care.