Atlanta airport currency exchange question?

Hey guys I got a question about the currency exchange at the ATL airport. Does anyone know how much it costs to use? I don't need to exchange much just need to trade enough USD to get about 50 or 100 British Pounds. I have a currency calculator so I know what the exchange rate is. I was just looking for someone that has used it before and can tell me what the fee is. I've seen the window in the atrium a few times and that's the only one I know of. Anyone know of any others in the airport? Or the fee?