Magefan.com shop uses the United States dollar (USD) as a base currency. For a customer's convenience prices on the store are displayed in customer's local currencies (e.g. EU members see prices in Euro, British citizens correspondingly in British Pound etc.).
That is why during a payment a total you are charged with is USD. Also, USD amount sends to a bank account. A bank in its turn converts USD amount to customer's currency using own rate.
A bank's rate and a rate specified on our shop could be different. That's why a total customer is charged with can little vary from a total customer see on a Magefan.com product page, but it's always the same amount in USD.