The fact of the matter is this.
Are we going to have to overpay to get Greinke? Yes. Are we going to have to overpay a decent amount? Probably.
I am torn on this. In once sense, $160 million for 5 years could go both ways.
On the other hand, there is this to consider. We have to have an ace. No matter what. The current rotation we have cannot win a World Series. We need a workhorse we can bring out there. If we don't get Greinke, the only other option is give up the farm for a trade, then more than likely have to sign the guy again anyway.
Also worth noting, I have researched, the only top tier pitcher next free agent period 2013-14 is Matt Garza and Tim Lincecum. Garza is not an ace, and Lincecum was absolutely horrible last season. However, with a strong bounceback he could be made back into one. He IS an ace, that was off last season. Other than that there is noone.
In 2014-15, the doors open a bit with Kershaw, Verlander, Felix, Lester and a few more. However, many will probably be resigned.