I am NOT phenomenally wealthy. I make a decent living, working 70-90 hours per week most of the year. Being in solo practice means I don't have any partners to argue with when I want to leave town. I field my own calls no matter where I am.
These trips are not cheap. I know that. The drawback of solo practice is that when I'm not in the office, I'm not getting paid. So I have to figure out how much the trip will cost, in both actual price AND how much money I lose by not working.
So why do I do it? One reason. As Mrs. Grumpy says "The kids are here only to visit us for a few years". So I devote as much of summer vacation and other school breaks as I can afford to being Dad, and not Doctor.
As my Science Marches On Department says, "nobody dies wishing they'd spent more time at the office".