I am hopeful that the price on Greinke won't be that high in prospects just because of his "difficult" contract. The problem of course is that he has said he will not go to the Phils and it most likely involves going over the Luxury Threshold, which I seriously doubt the Phils will (or should) do. We would need to move one of our tough contracts at the same time, and none of our high paid players can really be moved except Arrieta, which would involve us sending multiple top prospects.
I honestly wonder what Moniak or Williams would bring back. Maybe a 2 year rental? Probably not that good (Moniak should have more value)
Last year Klentak creatively picked up a solid hitting catcher, OF and SS (although the OF and SS were defensive liabilities) without giving up any real prospects. Maybe he can find a few pitchers in the same method, but that does seem harder.