The agent is David Mulugheta. There will be no home team discounts. He is a "Super Agent" known for maximizing contracts. The Bears will have to pay to keep Fields.
Well "maximizing contracts" or not, there's only so much leverage that Fields and his agent have given his body of work and the fact the Bears own the 1.01 pick. Fields obviously won't get a "top of market" contract given those factors. It's not hard to imagine that Fields refuses a more modest contract now, and his play in 2024 is such he never gets an offer for starting QB money. It might be a "sign for Jimmy G money now, or sign for $4-5mm/year backup money in 2025" situation.
Right now he's 10-27 as a starter. He's thrown for over 300 yards ONCE. But he's a good team guy and runs really fast. What's the going rate for that kind of quarterback?
If you're strictly considering his running ability and "good team guy" aspects I'd say the recent comp for Fields would be Daniel Jones. But Jones had a solid late season push in the final year before his extension (which Fields has not) so I'd say he won't get Danny Dimes money.
If instead of his athletic profile, you're talking about the more holistic concerns about whether he was the "right guy" for the team to build around and whether he could actually win a Lombardi given sufficient tools, then the proper comp is 2018 post-AFC Championship game Blake Bortles (if the Bears keep him) or 2022 Jimmy G (who the Niners let go to be signed by the Raiders). Bortles contract AAV was around $18mm and JimmyG is $24mm.
One has to believe the Bears will quietly shop Fields during the offseason and see what return they can get for him. That will drive the decision about how to approach the 1.01 pick and if they trade down.