Maybe check out Grabr (http://grabr.io)? You can find the AirPods on a U.S. website (i.e. Amazon) and then go to Grabr and paste the URL to the Amazon product page and create an "order." Then someone flying from the U.S. to Buenos Aires in the next few weeks will make you an offer and then buy the AirPods and bring them to you. You don't pay anything until you accept the offer, and then whatever you pay is safely held by Grabr (i.e. an "escrow" of sorts) and doesn't go to the shopper until you take physical possession of the item. Shoppers are rated and have reviews which you can read before accepting an offer. I placed an order last night and within a few hours I accepted an offer from a courier with an "excellent" rating and 260 5-star reviews. He arrives in Buenos Aires in 10 days and I'll receive the item in the lobby of his hotel.
