Maybe $6 billion would break Khabib Nurmagomedov's resolve.
Nurmagomedov and Conor McGregor's rivalry is well known and turned personal prior to the former winning at UFC 229 in October 2018.
UFC President Dana White explained recently that a reboot of The Ultimate Fighter was in the works, with Nurmagomedov and McGregor coaching on opposite sides. Getting Khabib to actually sign on may have been impossible, though.
"The Ultimate Fighter with [McGregor] is good attention for him," Nurmagomedov said to ESPN's Brett Okamoto. "I don't want to give him this. I never give him this. Even if they give me $5 billion—even if they gave me the UFC—I never do this. This is good attention for him."
He appeared to close the door on another fight with McGregor entirely, telling Okamoto, "It's done."
Money talks, and a Khabib/McGregor rematch is probably the biggest money fight the UFC could run right now. With McGregor retired and Khabib firm in his position, it may never happen.