Dallas would want our 1st pick this year or next year. At least another pick like a 2nd this year or next years. Maybe also 3rd, 4th or 5th just because Jim likes throwing in picks in trades.
Now that they banked 3 picks they are going to want a roster player with a controlled contract (Virtanen/Stetcher/Gaudette) and a prospect (I am not going to bother trying/looking up how to spell his name properly 2016 1st round pick/Lind/Woo/DiPietro).
Dallas does not want garbage contracts going to them or players like Baer (regular players with short contracts, UFA status). Unless Benn is willing to hold out, which I don’t think will happen, he is stuck in Dallas unless he opens his list up to more teams than Vancouver.
Difference between Kesler and Benn is that this wouldn’t be a big distraction in Dallas as it would have in Vancouver. I could see Kesler holding out for a trade putting major coverage in Canada everyday and more pressure on Benning to make a move. In Dallas they are all Cowboys.