Whenever a currency gets exchanged into another one, someone is going to lose money and someone is going to make money, but it's always the banks that make money...
If we applied the interbank rate, we'll lose some money when we get payed, since the US$ are exchanged to EUR, at a less favorable rate to begin with, and with fees on top of that, applied both by Esellerate to send us money, and by our EUR banks to recieve it...
Also, since the exchange ratio is not constant, and we get payed after 30/60 days, another reason why we can't apply the interbank rate, is that the US$ might go down in the meantime.
And, third reason, we are selling from the US (Esellerate is an US company) so, when Euro users pay with EUR, the payment is first converted to US$, and then converted back again to EUR, when we get payed, by our own banks so, another layer of currency exchange is made, and everytime currency is exchanged, there're always fees added.
For all those reasons, when making the US price, we add about 7% over the interbank rate, which just covers all the various costs, so we'll finally get our 22.90 EUR...
