I feel your pain! We are having the same problem. Hawaii probably has this set up this way to "share the wealth" so to speak between the shuttles and taxis. I just ran a dummy booking with SPEEDISHUTTLE, for 2,4, and 8 passengers from port to airport. Respectively $40.00/$81.00/$143.00 incl tax and fees. Not as cheap as a cab, they got us, what are you going to do! Hope this gives you some insight,