Good Luck. My suggestion is patience and ebay.
If you are patient, you do not need ebay. The game is not that hard to get, I think I saw one recently sold on these forums.
Most of my extra 5's sold out immediately. Looking back, I probably sold them all too cheap. I "technically" still have 1 left, but I can't sell it because it's part of a lot. (I put together 1 each of my best Slugs to make a complete set with the intention to sell them as 1 lot on the bay) Maybe I'll just break it up. Not sure yet. Still undecided.
I still have plenty of 1's & X's in stock, but I'm almost sold out of 2's & 3's.
Oh and 4 sucks. Piece of crap game. Sorry excuse for a slug.
On ebay there is this one guy from spain username ocelete who sells a kit every six months or so. Maybe he's sitting on a nos and is confident he's the only one doing so?
Nailed it! Your tip was spot on, I acquired MS5 from that seller. Thanks!