HI ! this is my first post on this forum.
I happen to live in Buenos Aires, Argentina (born and raised) & I´m afraid I can answer to some of your inquiries right now.
First of all: the most extended drug here is marihuana, mainly smuggled from Paraguay, but there´s also a large community of personal indoor-cultivators. Social tolerance to this substance´s abuse seemed to growth significantly the last 5 or 6 years.
Now speaking of "real" drugs: YES, cocaine is the stuff of choise when it comes to hardcore abusing. The prices aren´t THAT low in matter of fact... and street dealers often mix it with almost anything you can imagine. However, being this close to Colombia and Bolivia, one old-time and well contacted consumer can get his hands on some high quality material. IMO coke is THE number one upper here, being used by almost everyone wanting to enjoy a wild evening, from young to old... it just became the cornerstone of the party-pack.
I recently had the chance to test some crystal-meth... man, that really hitted the spot for me!! Being almost too afraid to smoke it, I swallowed and snorted some. It´s usage isn´t too widespreaded (since it´s a newcomer here), and contacting a guy that deals it is not so easy at all.
LSD is pretty much an easy thing to get, the quality of it goes from birthday´s confetti to mind bending pieces of despair.
MDMA is often manageable in pure crystal form, but most commonly on pills. The quality of it covers a wide range of purity.
Ketamine is a more sectarian substance of the raver community.
RC´s... well THAT is something very rarely found in this corner of the world. I (being an old-timer in this games) had the chance to get my hands on some 2ci and 2ce from a street dealer friend of mine, who almost pulled my head off in the pricing... but it surely worth the bills. I´m now trying to contact an online vendor worthy of trust.
Hey: some europeans who use to visit this city certainly get their brains re-filled with coke; and make SO much fun out of it... just like childrens in a theme park.
Well... that´s it, as far as it gets in Buenos Aires, the nation´s capital.
I hope this serves !
:D