If I was the grandfather, I would have told the kid to put a heavy price on it too. If I'd bought, used, and took care of it for 30+ years, I'd want my grandkid to get as much as I can leave him. A high price will keep away the butchers that wouldn't love and care for it.
A neighbor bought a beautiful CC about 6 years ago. It had been well cared for all its life. The original owners' wife had no idea what it was worth, (he had told her to ask $800 but she thought that he was crazy) so she sold it to my neighbor for $50. He has used and abused it and leaves it outside. A fair price of $600 would have put it in the hands of someone who would take better care of it. Good Luck, Rick