I doubt this will happen even though Conor says it will and Manny's camp seem to suggest they're working on it. If they both need the money they should just fight people in their respective sports.
This is not the first time that Conor McGregor is trying his luck with boxing. Three years ago, he had a fight against Floyd Mayweather Jr. , which is regarded as one of the most revenue-earning fights in the history of professional boxing. McGregor got a paycheck for $130 million, while his opponent earned $280 million. There were more than 5 million PPV buys.