CapnZapp
Legend
In this case I think it is good dungeonmastering to defer to what the player decides. After all, it's his or her character.I do see a situation where a DM and player disagreeing on the age a PC dies.
What is gained by killing off the character? I mean: the player is obviously enjoying playing the PC despite it being 100 years old. So why not let him?
It's not as if the Ghost ability was designed to saddle the PC with a mechanical penalty. (If it was, the monster entry would specify what the penalty was instead of saying something very cool and atmospheric but mechanically meaningless)
Cheers