I’m not clear on your goal.
Is it to have a cool project to work on for the next five to ten years and spend three times what a running car would cost? If not then you need to think about what you want. I think it’s a great opportunity for you but only if you have the passion to finish it.
It’s fantastic you know & trust the seller, he probably has more into it than his asking price but that doesn’t mean someone will pay that much for it. Plus it needs some body work.
I think the support for you can be found on this board but really it’s up to you to decide if you want this HUGE (but cool) project. In simple terms think what each of these three areas will cost in cash & time: Mechanical, body & interior. In my head I’m counting in thousands for each of those.
Oh without pics five thousand seems fair.