Its so funny to me how many different versions of Argentina there seem to be.
I buy all my mens underwear in Argentina, have for ten years. I go down to Once, the wholesale neighborhood, and buy really high quality 100% cotton mens briefs, if you buy enough to make the minimum, about 20 bucks right now, you get wholesale prices. Half or less of what "name" brand costs in the USA.
I can get 6 kinds of exotic chips- thai peppers, vinegar and salt, and so on, at the fiambria 20 meters away across the street.
My neighborhood chino, 1 block away, has soft toilet paper, and fruit scented translucent soft soap bars, for about 1/3 what they cost at target.
I actually use panuellos (handkerchiefs) in my artwork, and, again, in Once, you can find all kinds of bandannas, in every color, for a fraction of US prices.
I have been buying Argentine made shoes since 2007. I probably have over a dozen pairs, here and in the USA. They are excellent quality, and none have worn out. But- they only make certain styles. If you want Nikes, they all come from the same factories in Vietnam, and cost double here. If you want Birkenstocks, same thing- double. Instead, you have to buy quality Argentine brands, like Aqua Patagonica, or Correa. (I wear a mens 12, 44 euro size. Never a problem finding my size)
The big thing you have to learn in Argentina is how to shop.
Its a country with crappy online shopping- nothing like Amazon.
Most stores dont have websites.
Mercado Libre has some things, but far from everything, and its impossible to use without a DNI (residency)
Instead, there are literally hundreds of small, family owned factories, and thousands of small family owned stores. Each has different stuff. There are many brands of most things- and it takes time and effort to learn where the good stuff is. But its here, if you look, and often, better quality than you find in the USA.
Things I bring-
Electronics- again, imports cost double. For many years Argentina has had the highest global price for new Iphones.
So- computers, tablets, phones, things like JBL bluetooth speakers. Bluetooth headphones. I bring things like my small DJ mixer, backup hard drives, and high capacity usb drives, and my ebook reader.
Also, cables and connectors. You can buy a cheap desktop monitor here, but the adapter for this years macbook to hdmi might be rare and really expensive. Real apple power supplies for laptops are a fortune.
Real saran wrap- the local stuff just sucks.
Spicy condiments- there are starting to be a few local hot sauces, and these days, Siracha is actually available, but if you cook, anything picante is still worth bringing.
All in all, especially in CABA, most things are available. If you buy local, they are cheap in blue dollars. Imported anything is usually double- that goes for anything from Whiskey to Porsches. So, eat local.
Odd things that are specific to hobbies or professions may not exist- for example, my architect friends in the usa use small rolls of light yellow tracing paper for sketching. Cant get it here, and architects here love it as a gift. They dont sell prewound bobbins for sewing machines here. I buy em by the gross in the USA. Some things I take for granted when doing home repairs are just not here- I had to bring an undersink filter setup for my water from the USA, where it cost 30 bucks- here they only have clunky countertop models that attach to the faucet. But none of that should affect you for a few month visit.