John has definitely covered all the reason why the collectability of the Ocracoke is scarce. But there has to be something else that initially brings the people to the Ocracoke.
Bob is right, there is nothing special over it compared to the st Auggie or Simon’s lighthouse but its secondary market is running almost twice as much. John’s exclamations probably covers most of that, except for what turns on the switch?

I think what turns on peoples switches to even look for an Ocracoke collectable starts with the Hatteras effect. Cape Hatteras has been attracting people to the outer banks before lighthouseing was popular. Once the tourists are in the area they look for other tourist attractions. Probably for years tourist missed the Ocracoke since it is off the beaten trail and wasn’t well publicized. But now with Internet, many new lighthouse books and tourist books listing the Ocracoke lighthouse as a tourist site, it is no longer hidden from the public. Once people have seen the Ocracoke light their switch is turned on to have a representation of the Lighthouse and then all of John’s exclamations kick in.

What is there about this “plain Jane” light that after people see it consider it one of their most rememberable lighthouses?

Ask Lighthouser or anyone else that has visited it.