I don't buy it. I get health insurance between jobs because I know American health care is very expensive. I know if I tear a knee ligament playing ultimate frisbee it could force me into bankruptcy. So I pay someone slightly more than the expected cost of sports injuries in a man my age to insure against that risk. The regulators force me to insure against a bunch of other risks too that I don't need. But other than that meddling, it's a pretty classical insurance market.
The real problem with American health care is just that it is very expensive compared to the rest of the world. We get better health outcomes on the high-end stuff in exchange (our cancer survival is tops), but overall health outcomes aren't great.
There's a lot more wrong with American health care than prices. I know a lot of people who simply can't get insurance in the US at any price because of how the market works - and some of them are in great health and have been forever. It's actually quite close to raganwald's 'flood plain' example, where the insurers will outright refuse or quote impossible rates.
And, as it happens, I can't buy insurance on the free market anymore either. I've never been hospitalized or needed surgery or been injured, so I used to get pretty affordable insurance and have no problem paying out of pocket. Then I saw a therapist and that was enough for every insurer I've contacted since to blanket refuse to insure me at any rate. According to the state agencies that regulate this stuff, that's how the system is supposed to work.
Now, you could say that this is how an insurance market should work - maybe the reason people like me can't buy insurance at any price on the free market is because it's not possible to turn a profit by insuring us, statistically, even if individually we are incredibly healthy and pay a ton. I can buy that explanation. But do you think it's morally right for people to be unable to access basic preventative care at reasonable cost, and be unable to afford emergency care, just because statistically 5-10% of the people in their group are expensive?
I think it's also worth considering the counter-example: group health in the US is comparatively quite sane. If your employer has a reasonable group health plan, you can count on having basic coverage, even if a pre-existing condition gets excluded for a bit when you first enter the plan. The employer's overall cost for the group might go up, but that's about it. A friend of mine found out that his company's rate for group health was nearly $2000/mo - apparently they had lots of high risk employees - but my past employer's group health rate, in comparison, was around $400/mo for good coverage.
When I see a market behaving insane, I want to know what market incentives and government regulations are distorting it. In your case, the knowledge that you saw a specialist would make a logical underwriter raise the price, but you should be able to get insurance at some price.
The big regulation that I know of is the tax treatment that makes it much cheaper for insurance to be purchased through employers. This has prevented a robust individual insurance market from developing - it would be very costly for the insurance companies to build out this service for a small percent of the market.
The other major regulations that increase cost and reduce choice are required coverage regulations. There is always some heartstring pulling to get treatment X included in the required bundle.
The real problem with American health care is just that it is very expensive compared to the rest of the world. We get better health outcomes on the high-end stuff in exchange (our cancer survival is tops), but overall health outcomes aren't great.