This is true we work with emergency management in Hawaii. Look up the Jones Act. All shipped goods end up having to hit the mainland before going to Hawaii which is a major contributor to increased costs of goods there.
Land anywhere useful is also extraordinarily expensive and developing industry is commonly blocked on the thinnest of reasoning. Hawaiians even sabotaged the interisland ferries on some trumped up environmental concerns (they complained a couple people loaded sands or rocks) seemingly being scared shitless of their own people from other islands having cheap access (the tourists just fly so it has nothing to do with overtourism concerns). You can hardly develop any infrastructure that's not tourism or residential, and residential is also usually tough outside the big island.
Also the various cultures on the islands have a tenuous peace as a legacy of cane plantation owners purposefully segregating and pitting the natives, Chinese, Filipinos, and whites against each other. This lives on in everyone sabotaging the development of any other part of the islands and things like 'Kill Haole Day' in the very welcoming public schools.
As a result of this everything is even more expensive than just the shipping and isolation issues.
A quick google search on jones act and hawaii reveals this page hosted by International Longshore and Warehouse Union (ILWU)
https://www.ilwulocal142.org/news-item/jones-act-fact-vs-myt...
Few things listed there are clearly false.
"Myth #2: The Jones Act Raises Prices for Hawai‘i Residents.
However, a comprehensive 2020 study by Reeve & Associates and TZ Economics found that this is simply not true.
Their survey compared the prices of 200 consumer goods—including groceries, household items, clothing, and automobiles—at major retailers like Costco, Home Depot, Target, and Walmart in both Honolulu and Los Angeles. The results showed that prices in Hawai‘i were, on average, only 0.5% higher than on the mainland, a negligible difference that cannot be attributed to the Jones Act alone."
As a frequent visitor to Oahu, i stop by Costco on the way from the airport and i can see that most consumables including milk and meat is 30-50% more expensive than at Northern California Costco. This is representative across local supermarkets as well.
So its seems that this union is trying to minimise the impact of shipping on costs of everyday goods
Critics dismiss this study as bogus:
https://www.grassrootinstitute.org/2020/07/shipping-industry...
"using online prices to compare food prices at Hawaii versus Los Angeles stores is problematic. A visit today to the Keeaumoku Street Walmart showed an 18-ounce box of Cheerios selling for $4.26, before tax, versus $3.64 for its listed online price, and a four-pack of 5-ounce cans of albacore tuna for $8.43 versus $6.74 online."
That is actually true, Keamoku Walmart does not pricematch to their online prices and the only way to get those prices is to place an pickup order and wait for several hours to pick up at those prices.