Belly

Beli (ベリー, Berī) represented by the Beli sign: is the unit of monetary currency in the One Piece universe. It is almost exclusively depicted in paper form although coins do exist. Although closely resembling United States dollar bills, the large values on the notes harken to the Japanese yen. The Beli has no fractional unit.

In the SBS of Volume 53, Oda showed the designs on the coins and notes of One Piece.

Distribution of Wealth
When Oda discussed the Doskoi Panda brand, he mentioned that the line was very expensive. With this is mind, to properly put the currency's value in a real world context, a 10,000 shirt is expensive to the people of the One Piece world. Rare Adam Wood, in contrast, being sold on the black market can reach the price of about 200,000,000.

Bellemere was noted to be too poor to give her daughters everything they needed in life, and when Arlong invaded she had only a life's savings totaling at the time just 100,000 and had prior to this often been on a diet of just oranges to pay for the life she had to offer her daughters. She was the only one in her village unable to pay the full amount Arlong requested at the time of his arrival, (100,000 per adult, 50,000 per child), and Arlong continued to demand this amount regularly from the residents of Cocoyashi Village resulting in years of struggle to pay the amount to avoid anyone being killed by Arlong. Arlong had agreed with Nami that she only had to bring 100,000,000 to buy her village back off him, an amount she took 8 years to amass and almost succeeded in reaching the goal simply by robbing pirates knowing they had access to more wealth than citizens. Notably also, Nami once demanded 1,000,000,000 from Igaram to protect his country's princess calling it a "measly" sum for a royal household to have, but later it was noted that the country did not even have this amount of wealth to offer as it was on the verge of civil war.

The Straw Hats considered themselves "wealthy" after gaining gold worth 300,000,000. When they lost 200,000,000 of it to the Franky Family they noted their remaining 100,000,000 was still enough to buy a decent 2nd hand ship to continue their journey, even though their original amount would have bought them a brand new ship of much better quality. The most affordable slaves are humans at 500,000 while 70,000,000 for a female unsplit mermaid is the highest starting bid for any race. As such, all kidnapping groups seek them out and they present the most profitable slaves at auctions, and the storyline hints they can run well into the 100,000,000s, being noted only to be bought by only the wealthiest of the One Piece world inhabitants.

However, to a World Noble, a bid of 500,000,000 seems to be an insignificant amount of money to them judging by the way Saint Charloss bid in the Human Auctioning House. And most note worthy, he bid this amount off the mark and no one else could counter his bid in the auction house ending the sale of Keimi then and there. His father merely noting his 'waste of money,' indicating they have even more wealth than this and while this amount is still considered a waste, it means they do not go through the same scale of financial concerns as the rest of the world. Also, while the limit of bounties is unknown, the highest known amount for any bounty is Donquixote Doflamingo with a former bounty of 340,000,000. However the fact the officials would consider offering this amount also indicates that the treasury for holding bounty rewards has a considerable amount of money to offer or are at least willing to offer and part with that high of an amount.

So it would seem that the difference between the amount of money possessed by the richest and poorest of the One Piece world citizens, the poorest families can have less then 100,000 life savings while the richest have a staggering 500,000,000 or more.

Known Prices

 * To rent two Yagara Bulls: 2,000
 * Doskoi Panda brand shirt: 10,000
 * Rare Adam Wood: 200,000,000 (Blackmarket price)
 * The sword Wadō Ichimonji: 20,000,000
 * The sword Yubashiri: 1,000,000
 * The sword Sandai Kitetsu: 13,000,000
 * Slaves: see Selling Slaves
 * To buy Cocoyashi village from Arlong: 100,000,000

Other Currencies
Although the Beli is a universal currency used nearly worldwide, some isolated countries have their own currencies. As of now, two such currencies were mentioned:
 * The extol (エクストル, Ekusutoru) is the currency used in Skypiea. Normally written as a capital "E" with a vertical slash through it like a dollar sign: . The Extol seems to be pegged to the Beli, there are 10,000 extols per 1. Nothing else is known about the extol.
 * Gor is used on Amazon Lily. Same for extol, nothing else is known.
 * In the Boss Luffy specials the currency Rio-beli is used. This currency has no banknotes, only coins, and mirrors the Tokugawa coinage that was used in Japan in the Edo period.

Translation and Dub Issues
It should be noted that because of the phonology, multiple English spellings exist; the most common among fans is "Beli", although "Beri" is also used. "Berri" and "Belly" are used too but are somewhat uncommon. "Berry" for singular and "Berries" for plural are used in the English versions. The author has spelled it both as "Berry" and "Belly" on the actual bills.

Trivia

 * Nami's eyes tend to take the shape of the symbol of Beli when she hears that a large amount of money is involved. Especially when explaining that what she is doing has nothing to do with the money.
 * In appearance and denomination, the Beli closely resembles the Japanese Yen (日本円 Nihon En). The characters Yukichi Skull, Ichiro Kumaguchi, and Hideo Usaguchi portrayed on the Beli banknotes are a pun on Hideyo Noguchi, Ichiyō Higuchi and Fukuzawa Yukichi portrayed on the corresponding yen banknotes.