The place where old books are concentrated is the small park on the east side under Mianyi overpass. There are more people on Saturday and Sunday, so it can be cheaper if there are more people.
Another place is the Zhao Yan Art Market opposite the east gate of Lianqiang Community in Lian Meng Road. Now all the antique sellers have moved away, and the old books may still be there, but there are still people on Sunday.