Thanks for you're information. Yes maybe I'm a bit wrong with my information about some games. I think it's also the difference between the UK, where the distribution of NGP was much mbetter then in the Netherlands, we're distribution stopped after the release of Dark Arms. So here you won't see that many clamshell versions of Sonic. Also I had much more trouble catching Dive Alert Matt, then with the Becky version, but that was years ago.
About Pocket Reversi, I know three owners in The Netherlands, got mine last year for only 10$ brand new.
About the b/w games, I think KoF R-1 is the most common of the English. I see that one popping up every now and then.
Oh and you have a great collection oh and if you find some other copy of Neo geo Cup '98 Plus please point it to me as I really want that game.