The standard going price for the genuine LP-E6N, as used in the 6D and many others, is about 68. Even a "grey" seller such as HDEW only offer it for 60, not much of a saving, DigitalRev (who are usually one of the lowest priced grey market sellers) actually charge 72.45. So any EBay seller offering a "genuine Canon" battery for less than 60 may well be selling fakes. If something looks too good to be true, it probably isn't true.