Manny Pacquiao wants to fight Floyd Mayweather Jr. for free. But don't think for a second that this long-delayed superfight wouldn't be the biggest cash cow the boxing world has ever seen.

"Wise fans may question the motivation to fight for charity," renowned boxing oddsmaker Joey Oddessa tells Covers. "Let's be real. Boxing is a business and a risky one where sadly one bout can ruin a fighter. I think it will take place if Manny doesn't retire or get beat again but not for free."

Pacquiao stunned the sport this week, proposing that he and Mayweather finally step in the ring and donate all the proceeds to charity – something that doesn't quite sit well with a guy whose nickname is "Money". Mayweather shot down the proposition quicker than his counterpunch, but the idea has sparked discussions about what could potentially be the biggest bout in boxing history.

Fight fans were so close to getting this dream matchup in January 2012, when the two sparred on Twitter and it seemed like the ball was rolling. But an agreement to disagree – on just about everything inside and outside the ring – KO'd Pacquiao vs. Mayweather before the bell could ring.

At that time, Mayweather was a -160 favorite against Pacquiaco (+130), who had yet to lose his welterweight title to Timothy Bradley or get dropped by Juan Manuel Márquez. Since those two losses, "Pac-Man" has rebounded with a win against Brandon Rios but the shine is off the Filipino star for his struggles in and out of the ring – namely his tax troubles.

"I'm not a guy who likes to look in the rear view mirror, but I said this would be an easy fight for Floyd in 2011 if they didn't get Manny beat before he would get to Floyd and it still is," says Oddessa. "Fan's caught a dose of reality. They managed to get Manny beat not once but twice, the second in devastating fashion. Manny is a moneymaker much like Floyd, but Floyd's just that much better at both in the ring."

The possibility of a Mayweather-Pacquiao main event has had sportsbooks drooling over the huge handle this superbout would draw, especially if the venue was in Las Vegas – rather than Manila.

"For a fight like that, you get a lot of high rollers coming to town plus all the Filipino fans coming to cheer Pacquiao," Jeff Stoneback, sportsbook manager at the MGM Mirage told Covers back in 2009 when the fight was first purposed. "This would be a Top 5 all-time biggest draw, at least. If not the biggest fight we've ever taken action on."

And, five years removed from that promise, Mayweather-Pacquiao would still draw in tons of action, despite the decline in Pacquiao's performance, especially if the two did agree to fight for free. Oddessa projects that Mayweather could open as big as a -300 favorite if the bout is ever finalized.

"Preview shows and raw emotion work wonders for the public's perception of who is going to win and the odds with it," says Oddessa. "Winning a wide decision against Brandon Rios in Macao, China helped (Pacquiao's) cause again and the charity talk will draw emotion."

"People will be betting with their hearts and not sense, in what I see as a one-sided boxing clinic by Floyd," he adds. "The price on Floyd will be higher than any prices listed year-to-date when Manny and Floyd were considered flawless by fans. But people will still back Manny."

For now, bettors settle for Mayweather (-1,100) vs. Amir Khan (+600), which is expected to take place soon, and Pacquico's rematch with Bradley, which is currently on the table.