I also bought a property in BsAs (Las Cañitas) in 2003 as a non-resident. Even then, new property prices were above US$1000/sqm in nice areas, and there has been a substantial increase in selling prices in the last few years.
Check on this web site
http://www.apartmentsba.com and look under
Argentina Real Estate Consulting & Property Management for a detailed explanation of the Real Estate process for non-residents of Argentina.
John