The best trade value is Cooper, despite what people are saying about his contract. The Cowboys gave up a 1st round pick for him knowing they would have to pay him that money and other teams will too. Also, Cooper is under contract through 2024 with most of his contract being salary. It can be restructured by any team willing to push his cap impact out a couple of years. If you think Cooper is too valuable to trade and worth the $22 million the Cowboys will have to pay against the CAP, then why wouldn't other teams feel the same way? The question is, what could they get for him. I seriously doubt they can get a 1st round pick for him. Houston got a 2nd round pick and a RB for DeAndre Hopkins. My guess is the Cowboys might get the 2nd round pick for Cooper and maybe a player.
Gallup probably has some value, maybe a 4th or 5th round pick. Tyron is a question mark because of his injury. A team in dire need of a LT may want him. Trent Williams was acquired by the 49ers for a 5th in 2020 and a 3rd in 2021. I suppose a deal for Tyron, who is a few years younger might look like that.
I am on the trade Cooper bandwagon because he does have some value and they need to clear some CAP room for defense. While Cooper is a great route runner, he is not my type of player. I would rather put the money into the defense because with their current defense they will never win anything. Cooper may be the best trade bait on the team other than Zack Martin who I would never trade.