There is no such thing as a "fair" salary, especially when you're talking about the differences between $300k, $750k, and $2 million. There is what the market is paying similar people, what leverage you can use to negotiate higher pay, and how much [above|below] market your employer is willing to pay to keep you away from its competition, among other things.

The entirely idea that it's "fair" to pay someone $400k a year to do a job but "unfair" to pay them $350k to do the same job is silly.