Excusing socialism because of the costs of socialism doesn't work well. Google up "circular logic".
So are you saying that emergency rooms should require proof of payment before they operate on someone? What if the person is incapacitated but has insurance but cannot prove it? What if he's been stabbed and mugged? Should the ER refuse him because might not have insurance and might not be able to pay his bill.
I would think that emergency room patients fall under the term "market failure" item: the purchaser is often incapacitated, and some sort of safeguard needs to exist to protect the ER against people who cannot pay. You simply cannot have a market in these conditions.