And yes, you can very easily argue that many other costs don't add value. That's why pointing to the superior overall life-expectancy in other countries is such an important part of the argument. On balance, every other system in the developed world does more, for more, with less. Our system offers bottom-of-the-pile rankings by every major measure.
Finally, "struggling with costs" is a non-starter as far as arguments against single-payer go since what things cost and how you come up with the money are clearly two different things. Saying "country X is having a hard time funding their health care system at 10% of GDP" in no way undermines the case for dumping a system here in the US that costs us closer to 18% of ours.
Seriously, we could make massive improvements to ours simply by picking the name of any other OECD country from a hat, and just implementing their system. Literally anything is better than what we've got here, and it's not even close.