I don't think most people on this site would be victimized in a scam like that, because we've got the benefit of knowing the language. Sure, some of us stress out about the test, but I doubt any of us do to the extent we'd shell out a bunch of money to cheat. Not because we're more moral, just because we've got the benefit of a common language, and a lot of exposure to British culture before moving here. Most of us study a book and take the test.
Are you involved in the production of that guide advertised on that site by any chance?