Bagwell and Lavigne each make good points... seems like a big roll of the dice, to me. Hard to pick a side on this one. (let alone not making much sense from a small market perspective)
I will say this --- If the Sox don't plan to make any other major signings/trades to turn this team into a championship contender in the next 2 seasons, we might as well trade two meaningless years of Lester (even if he is good) for a #1 spec who could grow and begin to hit his prime as the team progresses.