Well I'm by no means an expert on this book but I knew that there was more than one printing. I believe the red cover is the first one, done by Imperium Games and is pretty rare, and all later printings were black. Noble Knight has this Fair/EX condition copy for $40:
http://www.nobleknight.com/ProductDetai ... GenreID_E_
Theater of the Mind Enterprises did a later printing in the 90's. I think another publisher may also have provided one.
Someone more knowledgable than I will hopefully know for sure.
You don't like your job, you don't strike. You go in every day and do it really half-assed. That's the American way. - Homer Simpson