I have quite a long thread on the on the Nikkor 8mm 2.8 AIS on the Nikon cafe , lens lust section.
As far as the value I have no idea. Value is very subjective, but to me, it's one of my most prized Nikkor's. It's make the kind of images that not everyone gets or likes. And that's fine.
However I can say that "I" really appreciate the 180 feild of view, and for me it's my minds eye.
I think you might find the price of this lens is going to go up.
Just more photos, saw a perfect non-ai go on ebay for $1000, and an ais with box and papers like new for $2100,
The boy in the red shirt can't wait to grow tall.