I personally think Bell really cost himself 10's of millions of dollars. If I'm a GM and I see a guy who apparently is willing to sit out a whole year because being the highest paid RB in the league (and all-time), wasn't good enough for him, I'm very hesitant to sign him. If you want to make the argument that Bell only declined the offer because there was a lack of guaranteed money, then my response would be, why would I want to give a 27 year old RB, who just sat a whole year, a lot of guaranteed money.
Another reason why I wouldn't necessarily give Bell much guaranteed money is James Conner. He's already doing better than what Bell has recently been doing. Not only that, there's DeAngelo Williams, Willie Parker, and Rashard Mendenhall. Is it that the Steelers always know a good RB when they see one or is their system? I'm more inclined to believe it's the system because the odds of consistently being able to plug and play any RB and him excel, is excessively small. So, why would I give a 27 year old RB with over 1500 touches (when history shows 28 years old and 2000 touches is the kiss of death of RB's), a lot of guaranteed money over a long period of time?
Had Bell played this season, he'd have made $14M and hit the free agent market coming off of a season where he likely finished as a top 5 RB and garnered something like Todd Gurley and got about $40-$50M guaranteed (possibly $60M total). That's anywhere from $54-64M that he could have gotten. Now? He's going to make a few million (if any), this year - call it $6M, and if I'm a GM, I'm offering him little to no guaranteed money at all. Something like a 4-year $50M deal (back loaded), with no guaranteed money. Meaning, if after 2 year years, where the front 2 has $20M, I can move on from him, I will. So, instead of about $50M from the start of this season until 2023, he'll get about $25M.