I think the Jays will get fair value for Happ but it will be a lot less than people think. In other words, rentals don't go for what they used to, and Happ is clearly not a difference making level talent (good pitcher but that's about it). If we get a couple of B/B- level prospects, that's probably what I'd expect, nothing more.
Now, if we were trading Happ and JD last trade deadline, when they both had an additional year of control, we might have been having a different convo.