Cheaper coverage can pretty much only be obtained by excluding people or limiting the benefit.
The US pays more for a lot of reasons. It isn't a one trick pony:
* Americans are much, much more unhealthy than Europeans on average. Way more obesity, way more smoking and drinking for addiction rather than socialiation.
* The insurance apparatus imposes a ~20% overhead outright on expenses, and puts further money on top by moving costs out of the consumers hands. They control what doctors you see and what procedures and drugs you get, and often do so in ways that are locally beneficial to the insurer but are more inefficient than a universal system.
* Hospitals and doctors, by being decoupled from patient expenses by the insurers, run rampant on spending and salary and hospital administration gets as crooked as insurance bureaucracy. Your healthcare dollar quickly ends up going 60% to bureaucrats and institutionalized middle-men expenses and only 40% to actual care.
Solving #1 is something that has to be done over time, and the only way to do that is to have a healthcare system, any system, that stops disincentivizing people from seeing doctors except for during crisis. The ACA did very little to fix this (it basically only mandated that some routine preventative care came at no cost to patients) and until you can get the general unhealthiness of Americans under control you can't get costs under control regardless of healthcare system.
The other two, though? Single payer solves them either immediately or with the market pressure of the entire US populations healthcare needs. Every other developed country that adopted single payer was able to use its influence to get hospitals and private insurance in line. That is why the UK now has one of the best systems in the world.
This is what I meant by services (and also things like birth control and so on that are mandated in the plans but "part of life" rather than related to a change in health or injury).
edit: and I think you were responding in part because the services are more expensive than they need to be. My meaning was that they don't drive up the premiums of the insurance all that much (and with the large deductibles, in many cases the annual premiums together are not the largest component of the patient's contribution towards a large medical expense).
