well, DET has a highly talented prospect pool (dont think Hank or Pav would have to be part of any deal) and at some point there are going to be casualties. The price would be high, but DET is in a position where they could afford to if they wanted. I've heard rumblings they'd like to acquire a 2C so Hank and Pav can play on the same line. They also wanted to add more scoring. Duchene fits both (and at an affordable hit albeit for only 1 more year). At one point, there were rumors about Duchene being shopped.
Is it a likely scenario? Certainly not.