Not sure if this has been brought up, but it would be interesting to see an analysis on production vs salary in terms of total value. If their production is close, obviously the guy who makes 1/40th what the other makes is more "valuable". It gives his team more financial flexibility to improve the roster at other positions.
I wouldn't actually use that criteria to cast my vote though. The MVP award should be for the player who had the most outstanding year. Who gives a damn if his team didn't make the playoffs? It's almost as dumb as voters who look at players' offensive stats when they're giving out gold gloves.