Have a look at whether hotel/accommodation prices on some of the other islands are any less eye watering (probably not, as we went to Maui earlier this year and wow, it hurt).
That's because having done trips to HNL (nowhere else on Oahu), Maui, Kauai and Big Island (Hawaii), HNL would be at the bottom of our list by quite some margin.
Inter-island flights are relatively cheap (especially if HBO) and frequent. You can also avoid crazy car hire fees because taxis/Uber will get you around smaller places with ease.
PS as this is a TP thread so chances are such an option won't get you anything extra.