I recall Frank Mir was paid $45K to get his head smashed in by a real-life Chaos Marine (Bork Lazer) in a Heavyweight title fight and the main event of UFC 100.
I remember staring at the screen in disbelief and utter disgust when the disclosed payouts were released.
Total gate of $5,000,000+, 1,600,000 PPV buys and a mere ~$1,800,000 in purse payouts.
If you look at this through the lens of relativity, i.e. the physical risk you were asked to incur (climb in a steel cage with a slavering steroid guerilla) vs. what the UFC made vs. the profile of the fight and event vs. what you were paid... it HAS to be the worst.
Fucking. Insane.