End user? Coin dealers, stamps, collector cars, specialty collectibles, antiques, domain names, gems, jewelry, flora, fauna...many uses. Difficult to give a dollar figure.
I think it is both brandable as well as generic which makes it appealing and I thing the keyword RARE will help carry it. There is such a broad spectrum of products, services, subject matters, or demographics that this could apply to.
An $xxx but it depends on who wants it and how bad they want it (gee, what a profound statement, huh?).
The best thing is to get it out there, park it, and market it and see who comes a nibbling.