It would be nice if this could be applied to places where I don't have a bank account and just need say, $500USD converted into another country's currency. My b

It would be nice if this could be applied to places where I don't have a bank account and just need say, $500USD converted into another country's currency. My bank here allows me to withdraw twice from foreign bank ATMs but I have a feeling they are messing with exchange rates and I'm still stuck with a bad deal. I won't even bother with real exchanges in the States or in the other country. Everything just feels like highway robbery.