I totally agree with you that it's an enormously complex system, but I wonder how risky a tiny bit of experimentation would be. Maybe it's worth upping everything by 1 dollar just to see? That would make a huge difference to profits. But maybe the hip customer base would notice the change and see it as a signal that their eatery has become bourgeois?
I have to disagree with your point 2: The blue-collar working man doesn't want to queue with a bunch of students for half an hour for his food, however authentic it may be.