Doesn't matter. What matters is where a person adds value. As I said, see Ricardo for details. Until you've digested that, we're not even speaking the same language on this subject.
And it doesn't take years to grok this. Comparative Advantage can be explained in a few pages and less than fifteen minutes of time. And to take away your last excuse for learning it, I've even found a place on the web to do so. Go here.
There is one caveat that some other people here have mentioned. Just because something (i.e. reading a radiology exam) used to be a high-priced skill that commanded lots of money does not mean it stays that way forever. As the expertise spreads around, and the supply of expertise increases, demand drops and thus price must drop as well. This is economic reality, and no government policy can do away with it.
That means those high-priced radiologists have to either (a) become more productive (via technology, for example), or (b) drop their price, or (c) move to something more high-value (e.g., reading some new-fangled diagnostic test).
Those of us in the computer business grapple with this problem all the time. It doesn't matter how much money we make today - we have to strive to become more productive and stay up to date as our current expertise becomes more prevalent and its value goes down.
Comparative Advantage is beyond the comprehension of the anti-free trade types.