While not explicitly stated by any official sources, the original game’s “madol” might be based on Japanese yen, while EN’s “thaumarks” are likely based on USD.
it used to be that 1 yen = 1 cent USD, and thus 100 yen = 1 dollar USD, which is how the currency was updated for EN: take the original price of something and remove the last two digits, and you have your madol-to-thaumark exchange rate.
Here are some examples from in-game:
An interesting result of this rate-exchange is that it was not updated within the game mechanics in the move to EN:
This makes sense as EN players would require far fewer thaumarks for shop purchases and leveling if the exchange rate was obeyed, but it means that EN players are paying $80,000USD for leveling that technically only costs $800USD.
The two zeroes are being removed from dialogue, but kept elsewhere.
This change over from yen to USD resulted in a challenge for Aniplex USA: sometimes characters will say that something costs 1 madol, which is 0.01 thaumarks. As 1 madol = 1 yen (1 cent USD) this is something the original game can do with madols, but EN cannot do with thaumarks.
Aniplex USA’s solution was to invent an entirely new form of currency that does not exist in the original game, leading to the creation of “sorcents.”
Interestingly, there have been at least two instances of EN not adhering to its own exchange rate:
The Albert chain that Kalim loans to Lilia is said to be 10,000,000 madol/yen which should be only 100,000 thaumarks/USD, but it was translated literally as “10 million thaumarks,” instead.
And in the Prologue the chandelier is 1 billion madol/yen, so it should be only 10 million thaumarks/USD, but was translated literally as “1 billion thaumarks,” instead.
A few more examples of the exchange rate at work:
Jamil haggles for a lamp during Firelit Sky, getting it down from 10,000 madol/yen (100 thaumarks/USD) to 7,000 madol/yen (70 thaumarks/USD).
Ruggie sells 30 cat carvings to Kalim for 60,000 madol/yen (600 thaumarks/USD).
Ruggie asks about a jeweled bracelet valued at 1,000,000 madol/yen (10,000 thaumarks/USD).
Jamil calculates for Grim how two shares of the 5,000,000 madol/yen (50,000 thaumarks/USD) prize for winning the VDC equals 1,420,000 madol/yen (14,200 thaumarks/USD).
Twisted Wonderland Reference Note 