When you need to purchase a book for cheaper than retail price, all you need is a Half.com account and the title or ISBN number of the book you want. I have found half.com to be the most efficient way to find a book cheaper than retail price with very little difficulty. Since I when I was in college, I have saved $1855.36 off of book retail prices. I have then sold over $1000 worth of books online so my total book costs since 2002 have totaled to just around $800. Finding the book on half.com should give you plenty of new, like new, and used book options depending on the condition you are looking for. If you need the book quickly (say for a college class), make sure to look only for sellers that offer expedited shipping options as it is only a couple bucks more than the media mail option. Since Half.com is owned by Ebay, it has a similar user feedback rating system. I would also advise to avoid sellers with zero feedback due to inexperience. It pays to only deal with reputable sellers that ship your books on time, state realistic book conditions, and provide delivery confirmation to ensure safe delivery.
Other quick checks I often will do after pricing through half.com is to make a quick scan through Ebay and Amazon. Many book auctions on Ebay will not be heavily bidded on and there are quite a number of Ebay stores that are dedicated solely to books. Amazon also has a pretty comprehensive inventory of new and used books by individual sellers. Be aware that buying books from individual sellers is different than buying directly from Amazon so that many book purchases may not be eligible for “FREE Super Saver Shipping.”
For the more savvy book searchers who want to find the best deal possible regardless of the site, you can try book comparison sites such as Bigwords and AddAll. You will probably find that many of the best deals found are through half.com, Ebay, or Amazon anyways. Some people may not be looking for a particular book so the local library book sales, flea markets, swap meets, and Goodwill would be some excellent places to get a book on the cheap. Why pay more for something if you don’t need to?