I'd buy a '52 Mantle and give it to his surviving sons...
This is an old clip. Maybe they have one now. They talk about not having his rookie card, but I think they are talking about the '52. Maybe they mean the '51 Bowman. But I don't know. I'd like to give them both of them. But I don't know if $100,000 would even be enough at this point.
https://www.youtube.com/watch?v=VUriWlOARlc&t=1s