Ya, I'd rather the Avs sell Hejda and pick up a valuable asset(Likely a 2nd) for him at this point over a resign.
Our Defense is already looking overpopulated next year with EJ, Barrie, Stuart, Holden, Guenin, Redmond already signed for next year.
Even as it is now, I think we need to find a way to move one of these guys in order to make room for a UFA signing/Bigras. I think its best to move on from Hejda, he was great while he was here and he will be missed but its time.
He should be quite valuable at the deadline as well, if the Avs openly make him available, a bidding war likely ensues which could potentially go as high as 2nd + Prospect, or even a late 1st if a team gets really desperate for help.