Is your car otherwise in decent condition? an '01 sport is the arguable gem of the E38 line- someone might be looking to dupe you out of it. If it's been beat on all it's life- you may have some issues. I'd be critically analyzing the diagnosis of "engine going" WAY before thinking of selling.
that said- miles / pics / how much do you want? (interest intentionally demonstrated to emphasize my point)
It's not what you buy, it's what you build- Unknown
EN90283 - Stabled for HG repair
DH06247 - Running like a champ