I must state immediately that I'm biased in favour

of British gaming products... This said, does anybody own a copy of Standard Games' Dragonroar? Dragonroar was a British fantasy
RPG marketed before its release as having a 'secret ingredient'. It turned to be a cassette (uhm, did I spell it right?

) for helping new players to understand the concept of a
RPG. How much could it be worth? I occasionaly search for it on EBay UK, but I have never found it. Am I simply unlucky or it's a very rare and valuable item?