A 4th for TQS is about right. He's a role player and he knows his role. He's better than Callaway and LJH so SP can use him in his primary role and a backup at all WR positions while also helping the other WRs and players adjust to SP's system. He'd have more value to the Broncos than Lance will have to the Cowboys so a 4th would be about right.
If he gets traded for a 4th, then he would get traded for the same round pick as a former 3rd overall pick that was acquired for 3 1sts.