My first apartment here, I didn't buy off plan, but I bought it prior to the building being finished and prior to what is called "aprobación de final de obra", which is the approval of the certificate of occupancy. It wasn't that different from any other transaction in the sense that I paid a portion of the money up front and then the rest when I signed the deed. However there were many additional charges that the builder passed on to us, that you wouldn´t have to pay if you bought an existing apartment: Gas and Electric Meter installation, legal and escribano costs to have the consorcio registered and all of the accounting books created (rubrcation), fire extinguishers in hallways, emergency lights in hallways and illuminated exit sign, hookup of cable TV system to building, and several other items that of course nobody thinks of were left to us to figure out. Then of course after the final de obra (and of course the bribes being paid to the building inspectors to approve it) the problems began, inadequate wiring, leaks in the roof, rotten wood on the deck, broken entrance door, builder left the worksite and never finished the sidewalk. Since there is a law that supposedly protects buyers of new properties from "vicios ocultos" hidden defects for 5 years after the purchase of a new property, the builder was responsible, but of course ignored us, so we had to pay a lawyer to get involved, threaten to sue and end up in court appointed mediation, and believe it or not he fixed everything. As soon as that was done I sold that place immediately, but it took about 2 years to resolve the whole issue and I did make a nice 20% profit on the sale. A huge headache but at least it was profitable.
One of my friends decided to buy what's called a "fideocomiso at cost" in Caballito. That's where they sell you the apartment before the building is constructed "de pozo" and you get it at a much lower cost but of course you have to wait about 2 years. So he sold his apartment and moved in with his girlfriend. Gave 20% of the purchase price to the builder upon signing the fideocomiso agreement, then was supposed to pay 30 installments of $1500 u$d and then the balance of the cost when the building is complete and it's time to sign the deed. Low and behold after payment #10, some building inspectors went to the construction site, found a ton of violations and closed the building site down. This happened in August of last year. They still have not resumed construction and they don't know when it will start again, however the contract states that he still must make his monthly payments, or he will forefeit his initial payment and all of the other payments to date. So he has no apartment, one under construction that he must still pay for and no date as to when the project will be complete. The builder who was SO friendly at first no longer answers his cell phone and has not contacted anybody. And his girlfriend who told him not to buy "de pozo" wants to throw him out because she's so angry at him (this new. apartment was going to be their marital home) So of course now there is a lawyer involved who of course knows how serious this is and will gladly charge everyone up the kazoo to sort this out.
So of course be VERY VERY careful if you do this, have a good lawyer review EVERYTHING and leave no stone unturned and every single "clausula" must be analyzed. The nice part is, if the real estate market holds up, you can get a nice apartment for below market value, and have some good equity immediately. However realize that you are in Argentina and many things can and will go wrong and to sort them out always takes a very long time and will cost a lot of money to resolve. Business people here rarely take responsibility if anything goes wrong and their first reaction is usually to hide from you before dealing with the problem.