Glenturret Limited Edition Valuation

Hi everyone,

I've recently had a collection of scotch handed down to me, and I'm currently in the process of trying to figure out what it is worth. I have been able to find current market value information on all but a few bottles in the collection, namely those from the "Glenturret Limited Edition" bottling. There are several of each that were offered...the 1972, 1980, and 1987. I have been able to find some information on the 1972 and 1980 in McTears' past auction history, but nothing really solid to go on. The prices on McTears have been all over the place between 2004 and 2008 and there is no trend that I could spot to establish a current value. All of the bottles still have their silk lined presentation boxes. Also, I am located in the US if this has any baring on their value. Any information or tips would be greatly appreciated. Thanks.