A few things to think about...
Peavy's N.L. ranking in ERA+:
2004 -- 2nd
2005 -- 9th
2007 -- 1st
2008 -- 9th
Peavy's N.L. ranking in FIP:
2004 -- 5th
2005 -- 2nd
2006 -- 3rd
2007 -- 1st
2008 -- 12th
Peavy's N.L. ranking in xFIP:
2004 -- 7th
2005 -- 3rd
2006 -- 6th
2007 -- 3rd
2008 -- 10th
Peavy is 27 years old. He's still a young pitcher. He's had a few injury issues, but has generally been durable.
He's under contract for 4 more years at $56 million, with a $22 million option for 2013.
You are talking about one of the elite pitchers in the game, who is still young, and who is under contract at a reasonable rate through 2013, when he'll still be just 32 years old.
You are talking about the type of top-of-the-rotation ace that the Rangers have been seeking for forever.
You are talking about a guy who should be able to front the rotation when the Hollands and Felizes and Harrisons and Hunters are coming up and establishing themselves. You are talking about a guy who can be your legit #1 when you expect to be a playoff contender -- which shouldn't be too far down the road.
Do you just give up whatever it takes to get Peavy? Of course not. But I think the Rangers have to be interested in him, and have to be willing to push hard to get him. Part of the point of having a strong, deep farm system is that you can make a big move like this without gutting the farm.
Sure, Peavy may not be willing to waive his no-trade clause to come here. Or the price demanded by the Padres may be too high. The medical folks may have some questions about his health.
But I don't think you can just reject out of hand the possibility of going after a Jake Peavy, given that the Padres are willing to move him.