Does anybody know where I can get cheap books in Manila? Used books may do. I need to bulk up on my to-read list again.

I agree with Mikaela. I once visited Recto to find a certain book that I need for my friend's birthday. You can try Booksales, too. It is my sister's to-go place whenever she wants to purchase something new to read. Another one is Cubao Expo. Certain stores there sells old books (even vintage comics and pocket books).