Record-shattering revenue totals for Manny ­Pacquiao's upcoming boxing showdown with unbeaten Floyd Mayweather could surpass $400 million, promoter Bob Arum told ESPN in a ­report on Monday on the sports network's ­website.

The welterweight title unification fight on May 2 in Las Vegas will generate $74 million from just over 15,000 tickets at MGM Grand Garden Arena, Pacquiao's promoter Arum told ESPN, flattening the old mark of just over $20 million for Mayweather's 2013 fight with Saul "Canelo" Alvarez in the same venue.

Promoters first aimed for $40 million, then boosted the ticket prices from $1,000 to $1,500 at the low end and $5,000 to $7,500 for the best seats due to huge demand for the ducats.

But organizers have now shuffled the number of seats in various price ranges and boosted top seats to $10,000 to raise the live gate total from $50 million to $74 million.

"It's crazy, but it is what it is," Arum told ESPN. "It's amazing."

Boxing's record for pay-per-view purchases is the 2.4 million buys from Mayweather's 2007 split-decision victory over Oscar de la Hoya, but with Mayweather-Pacquiao having taken more than five years to come together with the planet's top pound-for-pound fighters, expectations of 3 million pay-per-view buys at about $100 each could bring $300 million in sales for US, Puerto Rican and Canadian markets alone.

Global rights are expected to ring up ­another $35 million, with a record $10 million ­already spent for rights in the Philippines, where ­Pacquiao is a Congressman as well as an iconic figure.

Arum said Tecate beer, a longtime Pacquiao sponsor, won title sponsor rights with a $5.6 ­million bid, $400,000 more than rival Corona, a longtime backer of Mayweather.

Mayweather's camp receives 60 percent of the revenue with Pacquiao's side taking home 40 percent.