We entered Patio Olmos shopping centre to escape the heat of the city (middle of January) and we found a real bargain: the Black Grill Restaurant Fast 11. It is located on the second floor (Local 314), in the food court. It has very good meat at incredible prices, including two side dishes! In Buenos Aires, you can not find a steak or sausage for these crazy prices. We returned whenever we could, spectacular!
This is the best value pizza we've had in more than two months in Argentina. The prices are ridiculously low (25 pesos when we stayed in January 2014), and the mozzarella pizza is delicious: not too thick, crispy and plentiful, with good ingredients. The place is always busy, and no wonder. They are quite fast, and there is seating inside and outside, or take out. Besides pizzas there are salads, and burgers prepared by the "grandmother", or so they put on the poster with the daily menu.