In programming, there is a VAST difference in productivity between great and mediocre programmers. That's because programmers create tools that do work. Bad programmers create shovels; great ones create fleets of bulldozers. Bad programmers create buggy, slow code; great programmers create fast, working, robust code and meet deadlines to do it.

I know this, because I'm a mediocre programmer. I struggle for a couple weeks to build something, and I talk to my Rock Star Programmer buddy, who immediately suggests a better solution. At his job, he creates stuff in a week that I couldn't create in my whole life (or at least it feels that way).

So yes, I think he'd definitely be a bargain at twice my salary, and probably he makes more than that, and should. If I were going to start a company, I would definitely want some rock stars like him.

The trick is, you almost have to be one to know one.