No, I don't think they're paying for the same thing twice. In any case, I am happy to pay some taxes that help protect the general public against illness even if I NEVER get sick myself. It could be spent a whole lot worse than that, I figure.

Anyone who wants to opt for private insurance in addition to our publicly funded medicare, that's their privilege. Some people do get private dental insurance, precisely because it is not publicly covered. I've thought about it.