I got tired of the salary /WAR analyses years ago. I know that on average, one WAR is worth 8 million (or whatever value they are using now), but it varies a lot from situation to situation. Teams with bigger payrolls don't need to worry as much about salary. Also, performance becomes more important than salary when you need just one more player to win the division as opposed to being in re-building mode.
And from a fan perspective, it doesn't really matter that much. You just want to see your team put the best team on the field and are not concerned with efficiency.