From a historical point of view the early cars are important and here is why.
1. The first cars were quite different in construction technique and parts used on them. Many of the earliest cars were used for competition also.
2. The S30 was 1 of the cars that opended the door of Japanese cars and forced the world to take the Japanese auto industry very seriously.
3. So many of these cars were modified / destroyed / damaged and crushed that finding a good 1 now is very difficult.
Yes all S30's look similar, but then again a Holden Commodore VL Executive is the same as a VL Walkinshaw. You can build a replica out of an exec model but a genuine Walkinshaw is always going to be worth more. Now perhaps comparing such marquee's is wrong but I think you get the point.
If I could own a unqiue Z I'd be far more interested in owning a PS30-SB or 1 of the early Works rally cars, epecially 1 with the LY engine head.
I think the problem with the discussion on say Classiczcars.com is that a certain minority refuse to accept the fact that the S30 was not designed with the US only in mind. Rather a majority of sales occured there, given that the Z-car was far cheaper over there due to shipping routes which caused the car to become far more expensive in Europe and other taxes. Its easy to say after the fact that yes the Z did well in the US and therefore its was designed for that market, however I'm sure Nissan was thinking of trying to sell as many as it could everywhere.
HLS30 00013 is not the most important S30 to be found in existence but it is significant and important. Its just that people often overlook the other markets and other models, which in my opinion are far more interesting cars than the US market cars.
I'm not sure there was an argument in anything I said above, I just think I wanted to state a few facts lol.