For over fifteen years I have been heavily using the quite comprehensive book (new and used) search engines AbeBooks.com and BookFinder.com and, more recently, bookdepository.com. In the last several years I have done so consciously as an alternative to the ever monopolizing giant Amazon, that sets out to unfairly quash all competition (e.g. selling for less than they buy).
Well, surprise, surprise, they are all owned by Amazon! I have been feeding the giant in my quixotic contest against it!
BookfinderFinder.com founded in 1997 was bought by AbeBooks in 2005.
AbeBooks.com founded in 1996 was bought by Amazon August 1, 2008.
Book Depository.com founded in 2007 was bought by Amazon July 4, 2011.
It's like going to the store and buying the generic brand only to find that it is owned by the same Procter & Gamble which owns the generic along with the name-brand!
God help us all! Amazon, among various other computer monopolies, (Google included, which owns my blog! and my e-mail) is dangerous in it's power to manipulate the little guys.