I was visiting some friends in Honolulu way back in 1986.
One friend had an apartment across the street from the university. This was in the Minoa valley, North-ish of Waikiki beach.
We decided to shop at the Safeway up the street. Locally grown lettuce, "Minoa lettuce" , was $3.50 per head! It was the size of a softball!...no kidding.
The whole Minoa vally isn't more than 10 miles, from Waikiki to rock wall. It couldn't have been the shipping.