Cheap second-hand bookstores/antiquaries in Budapest

I am looking for places to buy cheap book (dictionaries) in Budapest. Last time I was there none of the places I found through Google Maps was there (so I only visited Vonnegut Antikvárium), and I am only gonna be there very briefly, so I would appreciate places you know in person.

Also, what is the word for a second-hand bookstore in Hungarian – “antikvárium”? I found régiségbolt, but it seems to mean antique shop with furniture and so forth.