Let's take a step back, here. Cliff Lee is nails in the playoffs -- no one disputes that. However, in the long-term, signing Lee for anything more than about 5 years and $110-115 million is a net-negative for the Rangers. Even that type of contract may prove less-than-optimal in the long run. For my money (and, yes, I know it's not my money), Zack Greinke is a far better option. Over the last four seasons (2007-2010), Greinke has never posted an ERA above 4.17, or a WHIP above 1.28. He has somehow managed to go 46-39 with a genuinely awful Royals team, and even added a Cy Young in 2009, for good measure. He has also been very durable, putting in 200+ innings for the last 3 of those seasons.
Meanwhile, Lee has been a really good pitcher during that time-frame, but he hasn't been substantially better than Greinke in almost any respect. His ERA during the 2007-2010 seasons has fluctuated from 6.29 in 2007, to a low of 2.54 in 2008. His WHIP has solid outside of that weird 2007 season as well, but not much -- if any -- better than Greinke's.
I guess my whole point in this is that, for the right package of prospects, you can have a 27-year-old Greinke, for 2 years and $27 million, with the option of giving him an extension at some point, depending upon performance. With Lee, you're getting a pitcher who is 5 years older, costs a LOT more, and will take a MUCH longer-term commitment to land. While it's looking optimistic that the Rangers may actually re-sign Lee, I will not be overly disappointed if we don't, as long as we make a serious run at Greinke.