As long as the means test is set very high so that it only allows the upper say 0.1% of the wealth distribution to opt out, i see no practical problem, though I'm philosophically strongly opposed. But you do realize two things, don't you? 1) there is no capitalist, free market solution to the healthcare problem, because medical pricing is inelastic, and 2) To get the maximum benefits from risk sharing, the risk pool has to be as large as possible. These are the reasons why these lovely sounding, so-called, free market plans can never succeed, other than for a small subset of the population.
For example, putting all the young and healthy in one pool, all the sick and dying in another, the poor in another still, and everyone in between in still another. Is a bad idea. If you do that in a capitalist economy, guess which pool the insurance industry will end up with? That's right! Good guess! The pools will be divvied up so the insurance industry takes on the lowest risk, and the government the highest. Everyone gets screwed except those that suckle at the insurance industry teats. This arrangement is the perfect plan if the goal is to maximize price. All the other free market economies in the world have long since figured this out and done something about it. That's why their costs are fifty percent or more lower than ours for a better result! And that's why medical expenses are the number one cause of personal bankruptcies in the United States!