I live in Maui and you are correct. In the last year some housing prices have doubled. There is no way most of the people who live and work here can afford to save for a down payment or make the payments. I just looked at a 70 year old house on 8k sq/ft lot in a crappy neighborhood for $420k! Gas is $2.65/gal. A gallon of milk is $7. And wages are low here because this is a tourist/service oriented economy. But every day is in paradise!!!!
I love Oahu - the cost of living here is helped some by the fact that we can use the commissary, low air/heating costs, gas $2.09 on post, and clothing costs fairly reasonable. With our daughter heading out of state for college in three weeks though, we'll be having to almost triple what her tuition here cost us. Our house, though, bought brand new 3 years ago for a little over 300K would now sell for over 500K. KHON frequently addresses prices on Maui, and I feel for you. Great place to visit, though. I love Lahaina.
Are you sure? Wow. On the Big Island we pay $3.50 (this is still expensive.)