The time of year you are going should be a bit cheaper. October through March is stupid expensive. And FWIW, the Big Island is the best island. If you can afford to island hop, I would strongly advise spending atleast two days there. The Manta Ray Night Dive was by far the coolest thing I have EVER done. And I have dove all over the world. The waters around Hawaii are the most pristine I have seen next to the Indian Ocean (Thialand) and the Caribbean (Grand Cayman Island).
JIC CROSS || BMS || Agency Power || Falken Tires