Vintage 1960s One of a Kind Dress

This is a Vintage, one of a kind, dress from the 1960s it was my grandmothers and she has asked me to list it for her. It was purchased from a designer dress store in Westfield New Jersey. It does not have any tags other than the size tag and a dry clean only tag. My grandmother said she spent $600 or so dollars on it, she could not remember the exact amount. It’s an adorably stunning cocktail dress in a Medium. It has a cream fabric with a shimmery gold threading creating stripes through out it. The material is stiff and the dress is very well made. It has a crinoline under skirt attached. The jacket is as adorable as the dress. It has padded shoulders with ruching and beautiful bead work on the front which matches the beadwork across the chest of the dress. My Grandma said that she has only worn it 1 time, and when she pulled it from her closet to hand to me, it still had the dry cleaning slip attached to the hanger. I am asking high, as I do not know what something like this should sell for. Price is negotiable.