No, because he is a rookie and not only does Cobb have another year on him, but is in a much better situation for a WR in Green Bay.
What does him being a rookie have to do with it? A rookie scoring on par with a 2nd year guy should not shift value towards the 2nd year player. Cobb is more situation dependant - why is that a good thing? When the Packers needed to win games to go to the Super Bowl, Cobb was invisible outside of a few handoffs. The gameplan wasn't to get him the ball; he's not their best weapon.
Again, for the record, I am not saying he isn't a valuable player - he is. I am saying his current price-tag is crazy.
You'd be better off adding a little to get Dez Bryant, or downgrading to guys like Nelson, Blackmon, or Shorts.