I was thinking that a restored version, complete with uncracked air box, decent paint, and non-holy mufflers would be worth more, to me, than this bike and I've seen many over the last few years shoe up on various sites for less.
You could easily assemble one on your own for under $6K -$8K if you took the time based on the parts listed on e-bay in a given week.
Not saying that someone wouldn't pay it, I just don't see it as worth close to what he's asking. But i'm not a sandcast guy myself so maybe there are those that would love it.