I may be mistaken, but believe it’s an additional 3.25 miliion against the cap this year if he’s traded. Certainly not impossible. Then next year you’d be paying something like 22 million? for him to not be on the roster.
Bills would need to weigh the impact. Can he still produce at a WR1 level? Probably.
Is his attitude and behavior having enough of a negative impact on the team to move him?
I would really only want to trade him if a 1st is coming back, or he goes off the deep end to the point you have no choice but to take the best offer and move on