Welcome to baseball in the 21st century.  Sorry, but this deal makes sense for the Tigers.  First off, they get Robertson for $4.25 million in 2008, when he may well have gotten more than that in arbitration.  They get Robertson for $7 million in 2009, again possibly for less than he would have made in arbitration.  And while $10 million sounds like a lot, it's at or below where the market is pricing average big-league pitchers who give you about 200 innings (as Robertson does).

As a free agent, I have him valued at $30 million over the next three years.  But the Tigers would have gotten him for about what they will pay him during his arbitration years--$4.5 (2008) and $7 million (2009)--without much risk.  If he has a phenomenal year in 2008 it's possible that he gets more in 2009, but if he pitches poorly they get him for less.  Why not just go to arbitration and take a small risk?  A small fluctuation in performance means little to the Tigers, but is quite significant to a single player whose livelihood depends on his talent.  The cost savings are supposed to occur in 2010 when he gets $10 million.  But I have him valued at about $11 million in his first year as a free agent, which isn't much of a cost savings.