You will see that it doesn't cost that much and it is actually quite cheap.
I'm from Canada and my experience was prescription drugs were cheap and emergency care was there for people who needed it but it's not a perfect system. Getting in to see specialists was like pulling teeth compared to my experiences in the US.
The best choice is probably a mixed system like Germany has. Everyone has basic and pretty comprehensive public insurance, but wealthy people can opt for even better private insurance because there is a market for that. The best of both worlds?
To me though, the biggest achievement of a single payer system can be the price of medicine. Greece for example, has had a single payer system and anyone with employment can't opt out from having his primary insurance with the public funds. So it is a pretty strict system. But this system along with some smart legislation has allowed for Greece to have enough bargaining power with big pharma and now we have some of the cheapest medicine in the west.