Cristóbal M.
Yelp
Every big city around the world has a place like this, a flea market so big it covers many squares and sells from cheap clothing to "used" cars parts.
That place in Santiago is El Persa Bio-Bio, where the best things they offer are used video games, casual style clothing (some stores are really good, selling real leather jackets for a quarter the price in uptown), astonishingly cheap furniture of high quality (check the "Mall del Mueble" page) and even some "unusual" stuff like cell-phones and computers (dont you even dare to ask from where).
Note that the whole place has a furtive, National-Geographic-in-India, shadowy appearance in it, even though many of the stores are from honest salesman so if you are going there better go with a bulky friend and most important of all, a native (and no so posh) speaker of chilean spanish; that or youll get inmediatly marked by the folks there as a "gringo" tourist and Oy Vey for you. Still, the cheapest place in town