The stuff at Easy is really cheap, in both senses of the word. If you are going to expect a lifespan of more than a few years out of it, I would skip Easy. Lots of Hecho in Chine there.
I hate places like Easy, Walmart, and Home Depot, and refuse to shop there except when there is no choice, myself. They have a few cheaply made things at low prices, no range of choices, and sales people who know nothing about their fields.
Blaisten is not the snooty, top end place- that would be Barugel Azuley, which has a branch across the street from Blaisten on Juan B Justo.
http://www.barugelazulay.com.ar/
Both, however, carry the complete line of the major manufacturers here, which means you can ask for, and get, the cheaper models there as well.
I dont know how many commercial plumbing supply places you have been in in the USA, but Blaisten is just like the majors I have bought from on the west coast- they do most of their business with the trade, architects, contractors, and plumbers, so they dont specialize in handholding for ordinary consumers who dont know what they want- but Blaisten has the entire range, from really basic cheap stuff, to fancy expensive, all in one place, with clearly marked prices and good stock.
There are really only a few brands in Argentina, so extensive shopping around usually doesnt help much- Blaisten and Barugel will usually have most everything there is to choose from.
Sometimes you can get a deal from a smaller, local neighborhood plumbing supply, but most times they are nicer and more convenient, but more expensive than Blaisten.
Generally, FV is the mid range, best bang for the buck brand for griferia and lavatorios.
http://www.fvsa.com/index.php
And almost every store you go into, big or small, will have FV. Makes it easy to fix, if it ever needs it, in the future, and its Industria Argentina, which I try to support.