I'm not sure about the salaries. Vocation-motivated people are already doing it. The rest needs a good reason to put their entire life, quite literally, into one single purpose. It's one of those professions that requires a complete dedication of free time, youth, health, mind, etc.
It does not require more than your standard 8-17. Know tons of doctors that work the same hours as I do and spend their free time the way I do.
If there are more doctors, it would require less of each one's time though.