I don't think the Sage would disappear based on the #items you have.
Yes, it did seem rather unlikely.
Though for balancing reasons, it could be that a Sage disappears after having supplied X items? Else a flock of advies could farm him seriously... A new sage is then created randomly on the continent(?)
I suspect he would after a certain amount. I would think two would be more than enough. Can't say about the new sage though...
