exchange rates

I opened a euro account yesterday and had to go to Ermita to buy euros. My sister and I were debating why all the money changers are lumped in that area. As an economist, I should have said"economies of scale" plus most of the travel agencies are also lumped in that area. Instead , I came up with this, Ermita used to be the center of the sex trade in the 70's. The sex workers get paid in different foreign currencies thus the presence of the money changers. Decades later the place still looked squalid, with "ukay ukay" (second hand stores) lining the streets. We went there with this fat stack of Philippine peso bills which we guarded atrociously because suspicious looking characters abounded. It was quite poignant that in exchange we got just one euro bill! I thought that scene in Eurotrip where they were treated like royalty in Bratislava because they had like 2 dollars with them was funny. Apparently it is only funny if you have the stronger currency. I would have fed 5 families in a month with that money here!