Marco’s Bounty at over 1.3 billion Berries (1,374,000,000)

Marco has a full name now: Polo Marco, son of Polo Gram, the man who went into partnership with Whitebeard. He came aboard as an apprentice more than thirty years ago and rose to command the first division as the Emperor's right hand. The bounty on him is known from his Vivre Card, and no scene puts a date on it. What the story does show is the weight behind it: after Marineford, the Five Elders single him out by name, the only one of the crew, among the few forces left that could still bring Blackbeard down.

At Marineford itself, Whitebeard tells him he will not be forgiven if Luffy dies. Marco kicks Aokiji away just as the admiral is about to finish the boy off, then plants himself alone in front of Akainu and tells Jinbe to get Luffy out, because he is all that is left of Ace's will.

The cleanest calibration comes later, on the Live Floor of Onigashima. Buying Chopper time to finish the Ice Oni cure, Marco holds off King and Queen together and admits that two men worth over a billion each is hard going. King stands at 1,390,000,000, Queen at 1,320,000,000, and Marco's bounty sits squarely between them.

He had not wanted to come. Beaten by the Blackbeard Pirates a year after the war, he was working as the doctor of Whitebeard's home village on Sphinx and feared Edward Weevil would strike it if he left. He came anyway, for Oden, knocked Big Mom's ship back down the waterfall, spread his flames over the Ice Oni victims to slow the virus and flew Zoro up to the roof. While he was gone, the Marines landed on Sphinx, and it was Weevil who drove them off. Marco has since retired from piracy for good. The bounty has not retired with him.