Thrift Stores in Barcelona?

i´m currently on the road traveling europe. I will be in Barcelona next week. Im looking for a store that has cheap second-hand suits.

I dont mean getting a good discount on formal wear... I mean CHEAP.

Basically, a friend im meeting up with invited me to an event where people will be ruining these suits in some sort of food fight. I i had known about this before i left i wouldve pack something. I did a similar event back in the USA some months ago and there is a store near where i live that had worn out cloths for very cheap. I was able to get a shirt, jacket and pants for around $25. It was old, alittle torn, and kinda big on me but since it was being ruined, i didnt care.

Thats what iºm looking for in Barcelona.

does anyone know any shop that would sell stuff like that. A second hand store that sells old cloths for cheap. This isnt something they put in a tourist book some i´m looking to ask some locals. (my friends not a local, he no help with this).

any info on shops or areas i should look for would be a great help.