Rosa Parks and Valuing the Property of Famous People

I've written lots of times (most recently, here) regarding the controversy in the estate of Rosa Parks.  According to this article, the parties are talking settlement.  The question involves whether Mrs. Parks' friend and associate Elaine Steele "used undue influence to convince Parks in 1998 to leave the bulk of her estate to the Rosa & Raymond Parks Institute for Self Development."  I can't say that I've ever heard of someone exerting undue influence to get someone to leave their estate to charity, but I suppose there's a first time for everything. 

One interesting issue involves the valuation of Mrs. Parks' personal property:

An auction house is cataloging Parks' estate, chiefly to determine what of value she left when she died.

But [the attorney for Mrs. Parks' nieces and nephews] said placing a value on many items is difficult, however. What, for example, is the value of a plate Parks used when eating with then-President Clinton?

This is an interesting valuation problem.  What's the value of...

one of my dinner plates?
one of Mrs. Parks' dinner plates?
one of Mrs. Parks' dinner plates used when eating with then-President Clinton?

Valuing everyday items that have value only because of the identity of their owner is tricky business.