Actually we found we got better rates elsewhere (El Chaltén hotels for example would exchange at the daily blue rate from DolarYa) plus the random restaurants w

Actually we found we got better rates elsewhere (El Chaltén hotels for example would exchange at the daily blue rate from DolarYa) plus the random restaurants were the ones usually offering the legit rate. Unlike the cueva, they actually don't have leverage, and would love to get their hands on some dollars. We never exchanged money like this, but were happy to pay the bill in dollars at the end (prices were never set in dollars). And the math checked out completely. Note we also came with a similar-ish mentality. Let's exchange early on and be set. But this misses out a key point (that hopefully will become less relevant). The currency devalues fast. Exchange early on and you might find yourself holding a lot less than you got. We spent a month in Argentina, and had we done this, we'd have taken a 9% hit just on devaluation.