I am a US citizen bringing a group of Americans to Argentina and I have to pay for bus and hotel services in US dollars. Because all US currency is converted in to Argentine pesos when it arrives into the country by banking or credit card, the only way to get US dollars into Argentina is to carry it! I have never done this before, but would like to know what happens at customs in Buenos Aires if you do arrive with a large sum of cash? I have no idea - is it taxed, taken away, put in jail?...
This is not legal advice in any way shape or form - and I suggest you get some. But my understanding is that it is illegal to bring more than $10k cash into Argentina, so I imagine you'd be subject to some form of penalty if found guilty. I've read, but can't verify, that the fine would be 50% of whatever you're carrying.
You do have the option of declaring the cash before you arrive. I don't know how that works, but if you contact the Argentinian embassy in the US I'm sure you could discuss it with someone and arrange official clearance. Maybe the rules apply only to personal cash, and because yours is business-purpose it maybe be able to get an exemption - speak to the embassy.
But, please do not try to run the gauntlet of customs, it could be very ugly for you.
Phil at the safety hub. about 6 years ago