If you’re looking for some great second hand shopping then check out the markets in Barcelona. You can start with Els Encants which is held on Monday, Wednesday and Saturday mornings; stalls tend to start packing up by about 12 so make sure you get there early to get the best second hand stuff. The market has everything you can possibly think of from shoes and clothes to kitchen sinks! If you're prepared to root through the piles of clothes you can find some real treasures… and make sure you haggle!
If you asked a lot of people where they got their furniture from they would tell you they picked it up on the street. It is very common to see piles of good stuff in the town centre, especially around the Gothic quarter. Every district has an allocated day of the week when residents can leave large items of furniture on the street for collection vans to dispose of them, but not if someone sports it first!
There are hundreds of vintage shops in the Ciutat Vella, in particular in Born and Raval; the side streets are filled with boutique vintage shops where you're bound to find some beautiful, unique second hand vintage pieces.