Not too hard to come by. The $124 price seems like the standard price right now for the Minathor 50; if you could get it at $90 like they mention in the text, that would be a good deal. See SAKwiki for the description of the 4 extra bits you can buy from Wenger, I think I paid $20 for them. If you want different bits it might be better just to get the ones you want from your watch equipment supplier.
As per my previous expose on the Minathor I think they are great, and super cool.