He probably made a ridiculous amount of money to be honest. There is a story that he met an old man on a train, who wore shabby clothes, and had a nice conversation with him. He asked his manager "Who was the at poor old man?". His manager replied "That was Cornelius Vanderbilt, the riches man in the world". Apparently after that, Langford dressed a lot less ostentatiously!
Relative to his greatness and accomplishments, I don't think he made much to be honest. No more than any of his contemporaries I'd imagine, maybe less considering he fought on for so long, continuing into absolute poverty and blindness before dying penniless.
Marvin Johnson made peanuts in the late 70's despite being a three time champ who participated in some of the divisions greatest fights ..
It's Charley Burley. Disaster after disaster promotionaly and tiny tiny purses. But made Springs Toledo's all-time p4p top ten in his book The Gods of War.
The fans perceptions of them as fighters, their accomplishments and place in history. I'd imagine that's what he was getting at.
My understanding is five figure paydays while opponents made big six figures .. he's pretty bitter about it to this day ...