I don't think the Bulls ownership, or management even, have a realistic perspective on their own team.
Plus, they really have no incentive to trade Butler for anything less than a king's ransom. He's on a long term, bargain-basement price for a two-way perennial All-Star.
Would you trade multiple Nets picks and/or Jaylen Brown plus Jae Crowder for Jimmy Butler? That's likely what it would take.