I have been thinking about getting one of these for some time, then this week noticed them for sale for $99.95 for a 77mm version!
Every other one I have seen has been around the $200 mark, so I grabbed at this, wondering if it was a misprint or something. It turned up today, and is exactly as described, a 77mm Hoya HMC NDX400 filter!
Check out the Discount Digital Photographics website if you are interested. Incidently their 67mm filter costs more than the 77mm!