@denviochi I would clarify that with the taxi driver prior to your arrival. If he's OK with being paid with a $50 bill, great, but I wouldn't wait until arrival and just spring it on him without asking. Most of the airport taxi drivers will carry enough pesos to exchange a $100 bill at maybe 5 to 10% less than the blue rate. That's what I did when I arrived for the first time - gave the taxi driver $100 and got all of my change in pesos, which then gave me enough pesos leftover to survive until I could get to Western Union or a cueva for the first time.
$40 for your first airport taxi isn't
terrible, especially if it's pre-arranged with someone who's going to be holding your name on a signboard or something, but as
@Neil mentioned, you can probably do a little better. For comparison I'm flying out of EZE in two weeks and flying with oversized sports equipment necessitating a utility vehicle, and the price I've pre-arranged to pick me up at my apartment is 40.000 (about $38 at the blue rate). Once you get the first airport taxi out of the way, most day-to-day taxi rides around the city should cost 2.000 to 3.000 peso at most, they're dirt cheap compared to anywhere in the States.
As far as Western Union, my last few trips have been pretty painless, in and out in less than 10 minutes. The key is to go to a larger office in a touristy area. There are a lot of smaller hole-in-the-wall kiosk type stores that purportedly accept WU, but those are the ones that will probably give you trouble if you try to receive anything over $100. I'm not sure what neighborhood you'll be staying in - I could probably point you in the right direction for a reliable WU or cueva location.
If all else fails you can just go to Calle Florida and there'll be someone hollering "cambio" every few feet. Ask a few different people what their current going rate is for a $100 bill until you find one you like. The cueva I use most often is on Calle Florida. Visa is indeed accepted almost everywhere and their rate is close enough to blue that there's not really a need to carry lots of cash.
As
@FrankPintor mentioned, tipping culture here isn't like back in the States where even the self-checkout screens are asking for extra money these days. I tip 10% in restaurants here, any more than that's probably overboard unless it's truly exceptional service. If my taxi fare is 2.500 I might round it up to 3.000 (mostly because I hate carrying around small bills). Often when I do this the taxi driver is confused and tries to give me the money back because he thinks I accidentally overpaid. I order food delivery once or twice a day via Rappi, and I usually tip the Rappi couriers 10%, or a little more (almost as an apology of sorts) if it's an extremely hot day or if it's raining heavily. I'm probably an outlier, but if I see someone juggling soccer balls with their knees while riding a unicycle at a traffic light, I'll give them 1000 or two if I enjoyed the show. If you tip, try to save it for the "above and beyond" type stuff, it's not necessary for buying a croissant at a coffee shop.
Me being from the U.S., I know it's sometimes hard to turn off the tip switch in my brain, but the more heavily you tip the more people learn to expect it and then eventually it grows out of control. A little goes a long way here, as I'm often amusingly reminded of. I recently locked myself out of my apartment and the owner (who had the spare key) was several hours away. So my neighbor called a friend of his who arrived with climbing gear and rappelled from the 14-story roof down to my balcony so he could enter and unlock my apartment from the inside. I gave climbing guy a 15.000 peso donation for his services which I thought was a steal of deal compared to what I'd have paid for a locksmith back in the States. Afterwards, my neighbor told me I was crazy for "overpaying" and I should have only given him 5.000 pesos at most. So if less than 5 bucks is what a local considers to be the going rate for climbing down the side of a building, you can see why regularly giving even half of that to a taxi driver can eventually become problematic over time.
Anyways, safe travels to Argentina, and feel free to PM me if I can be of further help.
