Trade Coin

Zodiac Currency
Gold Pieces and Trade Coin are used as currency to purchase items from anyone and anything that accepts it as payment. In Zodiac, if somewhat wealthy, you'll often see the message that you can only carry 3.6 million gold!

Solution
If you have to purchase from someone or something, and they want more than 3,600,000 gold pieces for the deal, you have to make an exchange at the bank.