I have one...
Going from memory here... this was 6 years ago...
The engine is NOS, was originally a different color, I don't remember which. It was sent off to legendary painter Bigevilone for white paint, looks correct. The tank wasn't painted... I think he said he didn't have plastic paint. As I recall it was $300+ for the paint job.
I was going to put this in a LI 2-speed frame but it never happened... I got busy & kinda dropped out of the mini scene.
$500 shipped sounds fair to me.