Why aren't the Kansas City Chiefs working on a contract extension for Eric Berry? Put simply because they don't have to. At least not right now. The Chiefs have time with Berry's situation.
As Yahoo's Charles Robinson writes, the Chiefs are in full-on draft mode right now. Berry's deal is not a priority as of this moment. However, the draft is April 28-30 and the deadline to get a deal done with Berry is July 15. That's plenty of time in between to work on something.
Why am I confident something gets done? Because a deal benefits both sides in the short and long-term. Berry would land another big contract on top of the big rookie deal he signed in 2010. Who doesn't want a huge signing bonus right now? The Chiefs, meanwhile, are not going into the season with less than a million bucks in cap space. A long-term deal with Berry would free up space so the Chiefs will absolutely be motivated to get something done.
As to how big of a deal, the safety market suggests somewhere around $10 million per year.