Borders B&M stores have the best bargain book sections by far. I've gotten tons of great books there over the years, most under $5.00. Every once in a while, they run a Buy 2, Get 1 Free sale on their bargain books too. Check them out!

The huge book thread is HERE

Bigwords, Linkified

1. Campus-I

2. For Eastern Economy Editions (Indian) First and Second

I would try charity/thrift shops. I volunteer at a charity/thrift shop in Houston. The books there are 50 cents for a paperback and $1.00 for a hardback book. Once a month all books are 10 cents for a paperback and 50 for a hardback! The books this place sells are in excellent condition and many are new. I have seen people buy as many as 700 books.

i always get my paperbacks from goodwill or salvation army and they charge 3 for $1. they are normally in excellent condition, read only once and have a wide selection and fairly new titles.

If you're interested in new, current books, you might consider Zooba. All books are $9.95 with no additional charge for shipping. This is a book club offshoot, so you have to buy at least 1 book per month or cancel your membership. However, there's usually at least 1 book per month that's worth buying for the price. Almost all interests are covered in both fiction and non-fiction. Many new selections are added each month.

Check with your local library. Many of them have at least annual book sales. Some branches may even have a small used book store. Also try second-hand places.
Lots of interesting stuff out there!

www.isbn.nu

I'm the third to mention it. Addall is amazing though. It has half.com and all the other retailers for new and used books.