It would cost more than Chicago could be reasonably expected to give. You have to remember, as much as Chicago could use another center...Buffalo's not exactly overflowing with them. Without Connolly, our center situation is worse than what Chicago's currently is.
I'd rather the Sabres just try to resign Connolly. If he stays healthy, he's worth way more than anything we'll get in a trade for him if we resign him. He'll also be a huge bargain because given his injury history he'll probably get a somewhat bargain contract.