iphotoxx via Amazon is discounting the Neewer 77mm MRC Variable ND Filter (ND2 to ND400) to only $15.04, when you check a 30% savings checkbox on the product page. They also have a great price on 82mm filters. There is limited stock remaining of this deal.
Amazon: Neewer 77mm Variable ND MRC Filter (ND2 to ND400) $15.04
