Informalmente: "bater perna" pelas lojas do Brás, da 25 de Março, da José Paulino, etc.
(Acho que não se aplica à Oscar Freire...)
Definition: to visit a number of shops in order to find the cheapest price.
E.g.1: You can save a lot of money if you shop around.
E.g.2: I didn't have time to shop around, but I managed to do all my Christmas shopping in one afternoon.
This phrasal verb cannot be separated.
Fonte: Knights English (anyone can receive free Daily English Tips and Event Information): http://www.knightsenglish.com/port/top.asp