For the true collectors edition of Shadow of the Beast, you need to look for the one that came with a T-Shirt! I bet that is either very very rare, or no longer exists complete.
I know exactly what you mean by being addicted to buying games. I got into that habit a few years ago. I had to find and buy all of the RPGs for the original Playstation. I hunted everywhere to find the games and did eventually find and buy every RPG released in the UK and the US. Took me over a year but was great to get them all. And I've still not played them all yet!