Bidder's Edge, a Web site that compares and searches online auctions, has counter-sued eBay.com Inc., the Internet's largest auctioneer. Filed Feb. 7, the Bidder's Edge suit charges eBay with monopolization, attempted monopolization, unfair business practices, and interference with contractual relations. Bidder's Edge, Burlington, MA, wants to be able to continue searching eBay. The suit was filed in the Federal Court of Northern California, San Jose. It comes nearly two months after eBay sued Bidder's Edge to prevent the biddersedge.com site from searching the auction site.