I'm thinking of trading one of these guys. What could I possibly get in return for them?

you can get 2 players for each of those guys in any trade but i'd look into getting rid of campbell, chris henry, LJ, and engram for sure in trades instead of Jeff Garcia, Willis McGahee,T. J. Houshmanzadeh, and Reggie Wayne but if you get rid of any of those 4 you should get atleast 2 players each for them