Here's a really good article from Sports Illustrated about Cobb and his contract situation.

http://www.si.com/nfl/2014/11/20/ran...en-bay-packers

But the reality is Nelson’s recent extension could prove somewhat problematic in Cobb’s contract talks, in that it’s a relatively club-friendly deal at less than $10 million per year. Given current market standards, and with the salary cap expected to rise significantly once again next year, Cobb will likely be seeking something north of what Green Bay is now paying its No. 1 receiver. With roughly $8 million of salary cap room that can be carried over to next year, the Packers have maneuverability, but how they value their top two receivers will be an intriguing subplot to their 2015 team salary structure.
It's not the standard for slot receivers to get #1 wideout type deals, but I gotta believe the Packers view Cobb and Nelson as being equally valuable to the team - especially in light of the rising cap - so if Cobb signs for anything less than Nelson's deal would be good value for the team I think. I could even see it go bigger and longer given his age but be about the same deal on a per year basis. The history on deals in that range (or higher) for a slot receiver pretty much starts and stops with Harvin - and we see how that's worked out for Seattle. Cobb brings the production to command $9 mil/yr. and also has the intangibles that have gotten in Percy's way.