Viper Transmission Value

[the68project]

Need some help please:
I have been offered for sale a Viper 6 speed and would love to put this in my 68 Camaro, but I would like to try and determine what the fair price would be. A local gentlemen around here bought this approx 10 years ago from Hennessy along with some other Viper parts intending to make a serious street machine. It has never been installed and appears in great shape. The current owner says he really doesn't have a use for it, and we should work out a price. Any ideas on what would be a fair price? I will add some photos to the thread shortly. Any help would be appreciated!