If it was anyone else I think I would be with you on that one.....
I think for sure their is some selfishness involved, but I would say it is more to do with his competitive spirit and the 'need' to play / compete.
I would like to think just like Claus, that Killer has made more than enough to live comfortably for life, and while he is doing what he is to achieve personal goals, the achievement of those will help the club.
I'm sure there must be one or two out there who aren't mercenaries....