In Palermo there are many, many touristic rental which are being sold.
They were bought by foreigners after the 2001 crisis put on the market decent apartment for the price of a garage in the US. It wasn't just the price of property that attracted to Buenos Aires many foreigners for over a decade, it was also the cheap dining and living. However, recently having a second home in Buenos Aires brings a lot of expensas and costs. Many rented their property even back in the days, and some started renting it after costs rose. This lead to a saturated touristic rental market, as more rental properties were made available for lower rates, and less tourists came to Buenos Aires as it became an expensive destination.
Therefore, foreigner owners took the leap and sold their properties while their property 'holds' decent value. Some have doubled their investment by selling today (in just 10 years).