The center diamond by itself is probably worth low end close to 35K--it's 3.6 carats. If there is some sort of proof it was Al's or better yet a pic of him wearing the ring I'd say it'd go for 100K+ easy.
Easily if they can prove it. If they don't have any pictures or video with him wearing it they're in trouble though. Looks like they have sold a few things though. Still pretty neat!
