The only reason a Sam is worth more (I reckon) is the result of the history, it can only be cos Big Sam (whichever Big sam you like) beat Porsche, and the whole country loves an underdog.
The more confusing side of this is why this has become so big in a country that seemingly worships all things german, and still derides all things Japanese.
But then - we are close to trying to understand how the classic car market works with this - I mean , pre production Range Rover (not immaculate) 70K anyone??
In my case - apart from the paint job, most of the Samuri bits had long ago dissapeared by the time I got it 12 odd years ago - when I bought it , I had no idea what it was (or wasn't) and it is , and always will be, developed as it goes along. No idea what that would do to the value, only what it will hopefully do to my smile.
I do feel that the value of the Samuri's will eventually be overtaken by the value of a very good Z , be that either standard, or "sorted" , look at totally top E Type's versus period racers, but it will depend on the market. I for one can't see how long this will continure for, before it crashes, and the whole thing will calm down again.
I cannot be alone in thinking that if I was to sell my car I could build a very nice Z and trouser the change, one that could do anything mine can do. BUT - I wont sell it at the moment, cos I like sh*****g it too much, and that is when we all boil it down, what we have them for - Samuri or not !
I know this doesn't answer the questions, but perhaps it helps. There you go - a Samuri owner , who says something!