The medication costs, especially the fluids, are much higher. I checked a UK pharmacy for costs for buying small amounts so the discount they get for buying in bulk suggests a very large mark up in price.
Did you include the cost of having a trained medical professional administer them? The cost of hospital aspirin isn't the pill it is the doc deciding to give them to you and the nurse who dispenses the pills( don't forget the billing person who charged you for the pills, the staff lawyer who was retained just in case you sue over the aspirin, and the payout to the last guy who sued and won).
As with every service industry from the local pizza joint on up COGS(Cost Of Goods Sold) is one of the smallest parts of the pricing puzzle.
If you read the recent Time cover story about medical costs, you'll see examples of people being recursively double-billed for items, at least according to the Medicare guidelines. e.g., and my memory's a little fuzzy on the specifics, but I believe one case was being billed for the operating room, then billed for the prep kit (which is supposed to be included in the room charge), then billed for every individual item in the prep kit.
If I hire a contractor to do something and he charges $X/hour, I don't expect him to mark up the materials he might use, too. I'm already paying for his time and expertise. I shouldn't also be paying the drywall for his expertise.
Hard to tell from the post, there was zero mention of staff costs besides the surgeon and anesthesiologist. So they fit in to the bill in one of two places equipment\drug cost or facilities. My guess is some of both. Time spent changing iv fluids is probably covered by the iv fluid line item vs time spent changing sheets being part of the facilities line item.
The medication costs, especially the fluids, are much higher. I checked a UK pharmacy for costs for buying small amounts so the discount they get for buying in bulk suggests a very large mark up in price.