Liriano is better than anyone we would acquire via trade or FA. Even if we only get "half a season" out of him it's still half a season more than any of our other starters.
I would rather spend twice as much on him than I would to sign two Marquis/Hernandez/Ortiz/Ponson's. You can't open up a season with Diamond, Walters, Blackburn, Devries, whatever ****ty FA we sign. You just can't.