Value of a 66 gmc stepside

[Youey]

Sorry if this is wrong place to post this, not new to these trucks I built a 69 stepside finished it last year. I have the opportunity to buy a 1966 gmc stepside that an older gentleman had started restoration on and since passed away. I'm set to go see it tomorrow to see what type of shape it's in. The wife has a price in mind already which I don't know or won't disclose til i see what it looks like. Really having a hard time finding what these trucks are worth and if a gmc vs a Chevy is any different. I would say this is a good project. So what would you pay for a project lets say in decent condition and not assembled.
Thanks for the help