There's absolutely no way you let him go for nothing. Let the hype build as free agency approaches - much ink will be spilled on who the big names are and Landry's will be among them. Near the eleventh hour, you franchise him; that's it. Any one of those teams with a desperate need will give up a 2nd and a 4th.
The bottom line is that the coaches don't feel he always runs the routes they call and is too headstrong to ever change. Whether fans want to believe it or not, that is a problem in this kind of offense.
The worst case scenario is you have him for another year at a price tag we can still afford after all the inevitable salary cap moves that are coming.
(And, by the way, you keep the 5th year option on James in place just long enough to get a low 2nd or mid 3rd rounder for him. Jesse Davis is unquestionably your starting RT next season.)
I've proposed both those trades and for some reason everyone thinks it's impossible and stupid.
I completely agree.