From Wikipedia; PriceGrabber

PriceGrabber.com is a price comparison service. They have partnered with more than 13,000 merchants, retailers, and sellers and provide free information on millions of products in 25 different categories. The company also serves as the data source for numerous other shopping Web sites, including AOL Shopping,Bing Shopping, About.com's ConsumerSearch, iVillage, Comcast, and CNET.

PriceGrabber.com was the first comparison shopping engine to project tax and shipping cost information for a consumer during the price comparison process.