King operated under the assumption that fighters would be more impressed with a stack of cash than they would be a written check. Most of the time he was right. Muhammad Ali was shortchanged some $1.2M by King after his "Thrilla in Manila" comeback fight against Joe Frazier. Naturally, he filed suit against the event's promoter, Don King.
King sent $50K in cash to a hospitalized Ali. As a condition of accepting the gift, Ali would have to sign papers effectually dropping the lawsuit. Whether it was because he needed cash or because his health was failing, Ali signed away his million dollar lawsuit for a mere $50K.