Bibliofind, the leading online antiquarian bookselling site, has been acquired by e-Niche, an online development group based in Cambridge, Mass., that specializes in collectibles. No purchase price was disclosed.Michael Selzer, Bibliofind's co-owner with his wife, Helen, said there had been several approaches to buy his company, but e-Niche's offer was the first that showed a concern for "preserving the values of antiquarian bookselling." He added that ownership by e-Niche would enable the service to be improved and extended.Bibliofind, which is run out of the Selzers' bookstore, Farshaw's, in Great Barrington, Mass., claims a list of nine million titles, and membership by 4000 booksellers worldwide. Its Web address remains the same: