Experienced travellers have suffered from these, and have learned how deeply they are screwed and are warned off. New travellers = their easy meat. Usually they have a 'share the cheat' with a local who install the ATMs in their shops = makes them spread = shooting fish in a barrel kind of game. We have similar ones in Canada that charge a fat fee, but consumer laws here make them state their fee of $1 to $2 per transaction = decline unless in desperate need. The difference is most do not offer assorted foreign currency (some at international airports offer US$ and Euros).