Mercado Municipal de São Paulo
Yes (incl. American Express)
Huge central market to see some exotic fruits. meats, appetizers, etc. Iconic building. Trash area but delicious food.
The City of São Paulo farmers' market aka "Mercadão" is a great place to taste local and imported food and spices. Not as cheap as one might imagine, it nevertheless provides a delicious experience for tourists and locals in a City historical building.