1) It's hard to really compare life expectancies when people in other countries drive less, shoot at each other less, smoke less, don't have such extreme income inequality, and seem to actually occasionally care about what they eat (
ie even with Canada's health care system, we would probably not live as long as Canadians on the whole).
the United States has the highest per capita health expenditures of any country in the OECDThis brings me to
2) Our delivery costs are
insanely high. Even Medicare, Medicaid, and the VA -- systems that use more or less one of the payment systems that the other countries use, Medicare being like France, Medicaid like Canada, and the VA like England -- pay more for the same services and drugs than other countries' systems pay. With HCR we're (slowly) moving the rest of our health care system to something like the way Switzerland pays for health care, but there's no reason to think that's going to lower the costs to what Switzerland pays, either. And already it's hard to find a GP that takes Medicaid, or increasingly even Medicare.
There's a town in Texas where the per capita income is $12,000 and the per capita Medicare reimbursement is $15,000. Without changing a lot about how doctors and hospitals do business, private insurance and single payer are both going to be way too expensive.