As you did what any of us would have. And the guys was lusting for the z like most of us have in the past and still do.
Some of us just see this as more of a win for you then the buyer but in the end if he enjoys it then t was worth it for him.
Heck, I can count a lot of stuff I paid top dollar for and use it way less then I thought. My 06 R1 for example. But she gives me goosebumps when I see her sitting there in the garage.