A person who can afford health insurance, but chooses not to buy it? Does such a person exist? I'm sure out of 300,000,000 people that applies to somebody. Not a common circumstance though.
It applies to more people than you'd think. For most people aged 26 to 35, buying health insurance is a terrible investment. Over three years, they could easily wind up spending $10,000 on health insurance -- more than enough to cover the kind of ER bill a person in that bracket might rack up. Further, even if they had health insurance, most types make them pay a part of their ER bill anyway.
Yeah I'm taking the risk that it won't happen, but I'm not willing to spend even $1000 a year against the remote odds I get cancer. At my age it's not much of a risk. Which of course is part of what's so messed up with the current system and why Obamacare is needed if there is no single payer.
Not that $1,000 would buy you a real defense against cancer anyway. Cancer drugs are stupid expensive, and any plan that cheap would have a cap on prescription drug benefits, yearly benefit caps, deductibles, and co-insurance. I don't get the point of buying cheap insurance, I really don't. I'd rather have nothing.