Of course foreign exchange offices have been doing this scam since forever ("no fees!")...
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Edit - note that with a bureau d'exchange my objection is not that they charge for the exchange; clearly that is the exact business that they are in. It's the "no fees" etc. marketing that hides from the less astute punters exactly how (and how much) they are paying for the service. I'd like to see that outlawed and direct costs of the exchange up front (e.g. "Exchange £100 for $121.5 at a cost of £10 compared to the base rate")