Mark, if it's a nice day today, take a walk in Barrio Parque. See the maids sweeping sidewalks, the butlers polishing Porches, the guards in their booths guarding the mansions. That's upper class in BA. $18K pesos won't get you close, la Nacion currently lists a smallish apartment there for $25K pesos/month. I think a lot of potential expats get some very misleading info on these threads.