Floyd Mayweather owns numerous championship belts and nicknames, and certainly a mountain of riches. He topped Forbes’s list of the highest earning athletes in the world, earning $102 million last year alone and upping his career purse total to roughly $420 million. The 37-year-old also reportedly earned a guaranteed $32 million from his fight against Marcos Maidana in September, and he set a new standard for athletes with his six-fight deal with Showtime for more than $200 million.

Clearly Mayweather understands what a huge draw he is for boxing, a sport with a very short list of marquee names, so a source close to Mayweather told Sports Illustrated he won’t give fans the super fight of the young century against Manny Pacquiao for less than two-thirds of the bout’s expected mega purse.

Rumors and speculation have swirled around a potential Mayweather-Pacquiao matchup for the better part of a decade, but only recently have negotiations reached a critical mass, and it seems Mayweather won’t put his undefeated record on the line unless a major payday is involved.

Pacquiao’s promoter Bob Arum told SI the two-thirds split in Mayweather’s favor wasn’t “accurate,” but that he has been talking to Les Moonves, the chief executive officer of CBS, who also controls Showtime.

Earlier this week, an Abu Dhabi-based investment group led by promoter M. Akbar Muhammad offered to pay $110 million to Mayweather, and the rest of the $200 million purse would go Pacquiao, a 55-45 split. That deal would also stipulate that the fight is held in the Gulf Coast city. Experts believe that the fight's purse could be well over $200 million.

Of course, boxing loyalists will say the money issue is yet another way for Mayweather to “duck” or avoid Pacquiao, a fighter blessed with the kind of speed and punching power that could neutralize the elusive counterpunching techniques that have kept Mayweather atop the sport for nearly two decades.

Though as the discussions continue, Pacquiao might have to accept the smaller purse. The 35-year-old Filipino superstar has won three straight fights, claiming and defending the WBO welterweight title in the process. But his bout against American Chris Algieri, held in Macau, China, drew less than stellar pay-per-view buys. SI reported that total buys were in the 350,000 to 375,000 range, but Arum put that number close to 400,000.

A victory or close loss to Mayweather would provide Pacquiao a major payday, and likely increase his appeal to fans in future PPVs. It's likely a rematch clause will also be inserted in any deal, guaranteeing even more for both fighters.

Nevertheless, even when the percentages for the purse are settled, Arum must still work with Moonves to make sure both Showtime and HBO, which has its own deal with Pacquiao, are satisfied. Pacquiao signed a two-year extension in May with Top Rank and its partner HBO that will likely result in at least four more fights, two in 2015 and two more in 2016, according to ESPN.