Lets for a second pretend that Crosby would actually want to be traded and the Avs would be the team he'd want to go to. You're realistically looking at the St. Louis return on steroids, which was Callahan, a guaranteed 1st and a conditional 1st based on making the cup finals (which the Rangers did). That was with St. Louis demanding a trade due to his Olympic snub and only allowing a trade to the Rangers.
Even with Crosby picking the location, I'd expect something like 2 1sts and a young roster player for him, possibly with a prospect on top of that as well.