if you think they are fakes, the best thing to do is drop an email to the company that makes them and let them deal with it, as they`d stand a better chance. Personally, i stopped reporting stuff years ago as nothing happens and i think they only really take any notice if enough people report them. If there`s only you reporting them, they`ll just think your a competitor trying to stop their listings.
In all honesty as well, if these do sell for over a £1000 and buyers think their getting the real thing for £100+, then that`s their own fault!