ESPN has Keller listed as the 36 ranked FA, ahead of Pagan, Finnegan and Maton. All who have signed bigger deals that 2/$12. They estimate Keller at 2/$22. I think that is much closer to reality.
MLB has him ranked 26th, ahead of Rogers, Finnegan, Fairbanks, Maton & Helsly. Many who have signed for more than 2/$12 already. MLB has him at 3/$36M.
So there you go. 2 other sources showing a much higher value. Do you really want to stick to your sources of info?