It has to be a typo, he made 50 grand for his fight before that. Or he figures with the millions he's made on bonuses why bother with the contract pay.
Well he made 50g BEFORE he signed a new contract coming into the Bendo fight. Not saying something is fishy and this could just be a typo, but maybe he new contract has some shady fine print deal to give the manager/Cesar Gracie the money or a cut first. Kind of like how the UFC had to pay Golden Glory before say Overeem and they would cheat him out of a chunk of cash.