G'day Brian.
How long is a piece of string?
Most think along the line that value is added the more original a bike is. So to the average punter the bike is worth less.
On the other hand people like me would go "that's tasty" and pay a bit more. A twin carb head with manifold/s is fetching $800 - $1K AU. I prefer the look of the older type tacho drive, add another $300. Then the minus side = seat, rear shocks (just what I can see from photo) = $400. So price down here would range from $8 to $12K AU. There are bikes for sale asking more but their STILL for sale!!
Cheers