I find that some of the designer stuff in Buenos Aires is expensive- but stuff like Martin Churba is not bad, for what you get- I am sure his clothes are more expensive in NYC or Tokyo.
I am a man, but I wouldnt be caught dead in a pair of Alden shoes- and they do cost $250 to $350 a pair, in the USA, in dollars- so I find places like Mancini, in Palermo Soho, where I get flashy, but well made shoes upstairs from the sale rack for $200 pesos or so to be quite a deal.
I also really like the Patagonia line of shoes- there is a store on Plaza Dorrego, in San Telmo, that sells them- elegant, unique, well made mens shoes, in the range of $300 pesos. Which, in the USA, would easily go for 2 to 3 times the price.
The thing is, in BsAs, you can often find shoes and clothes that are made in runs of a few dozen pieces at most- unlike the mass market stuff in the USA, which is dirt cheap, made by virtual slave labor in China, and without any design, quality, or verve.
Imported clothes are silly expensive, especially stuff like those quilted hunting jackets all the wanna be aristocrats wear on international flights, or Bally shoes- but there are reasonable local clothes by smaller designers.
For mens stuff, I like Hermanos Estebecorena, on El Salvador near the Pulgas, for example, where a very high fashion leather jacket is maybe $1500 pesos- which would easily be twice or three times that in a similar store in LA or Seattle or NYC.
I think the prices on genuine Carpincho coats and shoes are not bad, even at the fancy stores, and where else can you get shoes made from the worlds largest rodent?
The shirts from Balthazar, on Defensa, in San Telmo, are gorgeous- and pretty well made, as I bought one each (from the sale rack, of course) for my 14 and 18 year old sons, and if they cant shred them in a month, then nobody can- and they both look snappy and great almost a year later, with repeated machine washings.
If you look around, you can find interesting young designers, of both mens and womens stuff, that is not expensive by world standards.
Or, theres always Zaras.
Cheap. Generic, but a definite step up from trashy US stores like the Gap or Abercrombie.
Me, I buy local, where ever I go, and I find there is always interesting stuff if you look.