info please

[Teegirlm]

Hi. Can anyone tell me the value of a bottle of Cabernet Sauvignon signed by Sonny Bono? I need to know the approximate worth if any for inheritance tax purposes. I don't know if it would help to list everything on the bottle, but just in case..It says:Bono California Private Reserve and Cellared and bottled by Healdsburg Wine Cellars. I think it also says, 1989 or 1990. I really would appreciate any info on this that is available. Thank you.