damn you, mastercard

After the trip, here's the breakdown of the best way to get local cash.

The winner:
Visa ATM: Fee of 1%. Average cost relative to the real exchange rate: 1.1%. Cheap!

The rest:
Mastercard: Fee of 3%. Average cost relative to the real exchange rate: 3.4%. GFY, Mastercard. Thankfully, the US dollar dropped 5% from when I made the purchase, so effectively still ended up ahead... but not really.

Random exchange counter in the middle of nowhere in Patagonia with high demand and zero competition: Fee of 5%. Average cost relative to the real exchange rate: 5.2%