Don't IV's cost only $2 to make, but the hospital charges you $600?
If you ever read the report on the $6 Tylenol, it explains how the hospitals changed their accounting to assign overhead charges to every direct billing item they could.
You know how the garages now charge a hazardous material disposal fee, rag and miscellaneous supplies fee, etc? Imagine if they billed like hospitals. Those charges would be distributed according to what it took to deliver the service/part installation. They would also include profit to pay for electricity, tools, building maintenance, insurance, etc. Every overhead cost would be apportioned and assigned to everything you use/receive.
It's the concept hospitals use. For an IV, you're not just buying the IV unless you are stabbing yourself with the needle, using your own alcohol wipes, buying the needle, tubing and stand, performing the procedure in your house, and so on.
Military commissaries tack a surcharge onto every purchase to pay for their overhead costs, so the actual cost of the products can be easily compared to costs in other stores. But that OH cost is always there, whether they itemize it separately or add it to the cost of each item as a mark-up.