There are a lot of special deal sites out their for purchasing things on the cheap, but this one I have really begun to enjoy. I am a big audo book listener fan, currently my library over at Audible is over 1500 strong, and this is a new upcomer that also offers an inexpensive method for obtaining your very own audiobook library.
You can find this site at: www.chripbooks.com and begin your seach for bargain basement books to listen to. They have a wide variety that will open up your listening options. They have their own book listening control app for iOS and Android or you can listen to your selection through a browser as well. The app is not as extensive as Audible's but is quite functional.
So, if you are well versed in listening to books or just thinking about trying it out, this is a great way to get started.