I'm an auction draft rookie, so take this with a grain of salt, but here goes:
Losing Kendrick isn't that big of a deal I don't think. Frankly, I believe you can get similar production for cheaper from Asdrubal or some great upside from Sizemore. Nothing Kendrick has done would make me think that he's worth missing Hanson for.
That being said, I wouldn't stay in too much longer on Hanson either...maybe drive up the price a dollar more and hope you reach the other guy's breaking point. If he stays in, then you have successfully leached a couple bucks out of your opponent and get left with the more than adequate consolation prizes that should come cheaper of Anderson, Nolasco and Jimenez (in that order, based on the auction style, I would think). Make sure you get a gauge on the other guy though to make sure you can take the risk of driving up the price. Personally, I'm a big fan of Brett Anderson this year.