It's likely that the cost was nowhere near $12000. These huge bills are often the result of runaway price inflation and system-gaming and are totally untethered from cost.

Your assumption that "someone else paid for it" only holds if the price was directly tied to external costs and not their own profit.

So you say investors pay for it? Very generous on their behalf.

If a client rejects my initial quote but accepts my lower one (for exactly the same service), did I also 'pay for it'?

If the other clients pay the higher quote, and thus it is a better strategy for you to put a higher price whichonly a few haggle, you didn't pay for it. The rest of the customers subsidize the haggler.

Sure. But not exactly. No more than you paid extra when the bus boy dropped a load of dishes and broke them. In this case a mistake was made, and the business are the cost. It might have meant prices went up the following year, but I doubt it, as that wasn't really that much money.

Yes, they are fucking over someone else, by padding their bill, and hoping their insurance pays for it - which is why most of us are paying $2000+ /month, if we have an employer-provided plan. (keeps the real costs concealed from the people who are paying).