As you probably know, you cannot solicit them for deals until you establish a relationship, but you can get the relationship part started if you have an inbound lead marketing strategy to collect more leads.  

I sent to a guy in Fijithat is wanting to do wholesales with me this is his replygood research . but there are certain areas near beachfronts which has been declared by government as tourism free where foreigners can buy without any hassle and build.

I went on one of the tours, truly genius inbound marketing.

Unlike the other cities on the Hudson, it has not recovered - has not become either a commuter city or a cute antiques-and-tourism weekend travel destination.  

Plus, the Coravirus has had a huge impact on air travel / tourism, which then impacts airlines, which then don't need new airplanes.

No one has a crystal ball, but the climate, tech, and tourism industry boom would lead to continued price growth over long period is what I suspect.  

Besides tourism, there are nearby hospitals and universities to (possibly) drive some demand for this type of housing...Has anyone had success (or failure) with a listing that only allowed guests to book for periods of 30 days or more?

If you take the Riviera Maya for example, which is in huge demand (because you have all the pure investors in tourism on top of the expats), it is very cheap compared to the equivalents in either Costa Rica and North America.Finally, I totally understand your reluctance to invest in pre-construction.

It seems to me that investing in Kona may have some peculiarities due to the nature of the area as far as tourism, retirement, condos, etc.

Although the real estate there is very expensive, it's also very promising, the tourism there is booming!