Now that we're leaving, and no longer have to worry about break-ins or theft, I will confess that we actually brought our entire supply of USD (plus a $1000 USD emergency/contingency fund) with us in cold, hard cash! For our family of four, for a four month stretch, that was about ten thousand US dollars. (We undertook this trip in two legs, so that we had a three-month stretch from Sept - Dec., and another leg after the new year, from Jan to May.)
Having our entire budget at our disposal was a risky venture. For one thing, if we spent it unwisely, we'd be broke at the end of our trip, and unable to eat or get to the airport! Also, if we were robbed, we'd be SOL. But, given our limited budget and Argentina's outrageous withdrawal fees, we elected to take the chance.
So... where did we hide the $$$ you might ask?
Well, to begin with, after paying our rent in a lump sum up front, we used an envelope system I had developed and organized while still in Canada. Each envelope was numbered in a series (1 - 5) and contained three additional envelopes (labeled "a", "b", "c") and enough USD to see us comfortably through three weeks of groceries, transportation, "entertainment" (museums, the zoo, donations to local musicians and street performers, and so on). With an assumed blue rate of 10:1, this amounted to about $800 USD per three-week period for our family of four. That allowed us to dine out once a week as well. Roughly every three weeks, we'd head over to one of our Arbolitos and exchange our USD for pesos. Sometimes -- if the rate was lousy -- we'd wait longer and exchange two envelopes, which meant we ended up having to exchange well over $1000 USD at a time. (We'd also brought an emergency fund of approx $1000 USD for each leg, which we exchanged in chunks thoughout our time here as needed: We used our ER fund in the first leg for a bus trip to Iguazu, and in the second leg for some medical appts as well as to help with our Salta trip. We are coming back to North America with $300 USD left over.)
Our resulting pesos were organized into the "1a", "1b", etc envelopes, then hidden in various inconspicuous spots throughout the apartment, and inventoried in two digital locations.
Many of our envelopes lived between the pages of books on the bookshelf in the living room here: A travel book about Puerto Rico, for example, housed our emergency fund. Our "medical expenses" pesos lived in Panama, and $350 ARS for the taxi ride to the airport was stored between the pages of volume 4 of a 23-volume encyclopedia set!
Beneath the puzzle pieces there, our current and upcoming weekly envelopes lay nicely hidden from view.
Living on a cash system can be somewhat stressful, because it feels like one is always counting money. But for us, it ensured that we stayed more or less within our budget here, and never had to pay the outlandish fees to access funds from a bank machine, or be subject to the ridiculous exchange rates while doing so.