On February 23-27th the Treehugger Dan's Bookstore Cafe & Lounge will have the all day Spring Cleaning Book Sale.
This second-hand bookshop will offer hundreds or even thousands of books 350 forint each or 3 for 1000. There will be a few big tables set up for you to browse through this weekend.
These maybe not the highest quality books, but you may find some treasure.
At VI. Lázár u. 16
Feb 23 (Sat) through Feb 27 (Wed) 10:00-19:00