I thought it was obvious, but I'm sure OP meant that if you have an accident, you can't shop for providers - an ambulance or a helicopter takes you to a hospital, and you wake up with a gigantic bill. Not exactly "voting with your wallet", is it?
Perhaps there is some misunderstanding, but that (parent to my comment) was responding to a comment which indicated that there is too much government intervention, which is not allowing people to feel the direct financial impact of their medical decisions. People using epipens are not buying them 'just-in-time', they are planning ahead.
The great grandparent comment also seemed to be speaking to the way the government has incentivized employer-provided health insurance, which insulates people from making cost/benefit decisions. I think that if individuals had to pay $100 per juice box their insurer gets billed, they would likely find a way to cut costs.
