In short
The Hawaiian archipelago is the most remote inhabited land from any continent: nearly four thousand kilometres from California. That explains the cost of everything consumed here.
Honolulu is on Oahu, with Waikiki, Pearl Harbor and the Diamond Head crater. The other islands — Maui, Kauai, the Big Island — need a flight.
What it really costs
Hawaii is the most expensive state in the United States. Food costs thirty to fifty per cent more than on the mainland, everything arriving by ship.
TheBus, the municipal service, covers the whole of Oahu and covers it well, which makes doing without a car possible — rare in the United States.
What nobody tells you
The USS Arizona memorial at Pearl Harbor is free but requires an online booking, opening eight weeks ahead and gone within minutes. A daily quota is released at three in the afternoon for the following day.
Diamond Head and several natural sites on Oahu now require a booking and an entry fee for non-residents.
Sunscreens containing oxybenzone and octinoxate are banned in Hawaii to protect the coral. Those bought in Europe often contain them.