I hope so Ron! If it sounds too good to be true at that price, it probably isn't true!
I purchased a B+W Käsemann circular polariser on eBay. The seller was duly sussed out (like all I have dealt with and to date not had a single negative experience with) and some enquiries made. No problems found: that business brings in B+W filters from authorised Schneider Krueznack Hong Kong distributor so I was confident there were no tricks (especially the garbage circulating on Photo.net about "B+W authentic vs fake filters" — oh, pllllllease!!). Here in Australia, that filter would have cost $260 with postage. And eBay? $138, postage free.