Only time will tell whether Cooper is worth it to the Cowboys.
Hard to explain his steep decline after his first two years in the league.

Is it the scheme? The coach? The QB? The team? Or is it him?
After several games, teams get good tape on a player and figure out his flaws and design ways to exploit them. The player has to learn and develop to make himself more difficult to contain; some players never do.

I don't know if that's the case with Cooper or not.

But either there was a lot of competition for Cooper or the Cowboys got fleeced.
Hard to imagine that Cooper is the answer to what ails Jerry's Boys.