Froogle:
Developed by Google, Inc. One of the most promising price comparison sites to date.
BizRate:
One of the largest price search sites. Over 30 million products listed.
Shopping.com:
Child of Dealtime and Epinions, now merged to provide you with three shopping search engines that feature your products separately, yet the same.
Yahoo Shopping:
Complete Yahoo Shopping data feed creation and maintenance solutions.
MSN Shopping:
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NexTag Shopping:
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PriceGrabber Shopping:
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Ken Spelman Rare Books
Fine, rare, antiquarian, academic and out-of-print books. UK based, ships worldwide.
Kate Sterling Bookseller
Inventory of collectible movable and pop-up books.
Kane Books
Scholarly and antiquarian books.
Kolumb Internet Bookstore
Used, rare, antiquarian and out-of-print books (including first editions) specialialties include the former USSR, Oriental languages, as well as art, ballet and illustrated books.
Krazee4Books
Selling out-of-print, hard-to-find novels; anthologies, contemporary, historical and paranormal.
Keeble Antiques
Rare, antiquarian and out of print books, publishers end of line titles, deltiology, old photographs and antique maps. based in Dorset, UK.
Keogh's Books
Secondhand and antiquarian books. Search by author, title or keyword. Many out of print editions, specialising in arts and literature.
Kelmscott Bookshop
Collectible, out-of-print, and scholarly books as well as search, book binding and restoration services.
Ken Sanders Rare Books
Specialities include Edward Abbey, Wallace Stegner, B. Traven, Utah and the Mormons, and Modern First editions.