The peso has fallen (more or less) about 15% in the past few months. I am so glad I was there last week when I could ride the Subte for AR$0.90 (US$0.26) instead of $1.10 ($0.32). Without the peso fall, I'd have spent about $0.30 for the trip.
While I didn't do any high end dining, I did eat well, and, for example, 2 respectable pieces of dead cow, a respectable (not high end, but delicious) bottle of wine, and a salad (plenty for 2) came to US$67 when I saw it on the credit card statement. This, of course, did not include the cash tip. This same dinner would have been $100 more at home, and not as good. In fact, a friend was over a few days ago and went to a local Argentine home for dead cow. He described the meal (which included almost the identical wine). He asked me how much I thought the bill was, after he described what they ordered. I said $175. I was only a few dollars off.
Other ripoffs of last week included going to a little empanada and minuta place, and we ordered 4 empanadas and 2 sandwiches, to go. This came to under US$10, and was so much food (and tasty, too) that we actually threw some out (as it was lunch right before going to EZE).
Yes, I know a couple years back the same place would have paid us to eat there, things were so cheap, sometimes we must suffer the costs of inflation and pay a modest sum for a quality product.
Seriously, I have no idea, other than moderate to high end hotels, how Argentina is "quite costly." Often (and this is no reflection on the OP) people who think nothing of spending $10 for a single cocktail in the US, complain about a decent $40, wine included, dinner in Argentina.