Average salaries for each position according to Sports Illustrated:
Defensive Ends-$1.58 million
Offensive Linemen-$1.27 million
Defensive Tackles-$1.22 million
Wide Receivers-$1.05 million
Running Backs-$0.96 million
Tight Ends-$0.86 million
Note that these figures are two or three years old, so the numbers are likely a little higher now. But the proportions should be about accurate. Also, the offensive tackles are among the highest of all offensive linemen, particularly the left tackle (just like Sandra Bullock says in The Blind Side).