The cheapest way is to just walk.....
Actually you can take a respite about half way when the Nimitz crosses the Kapalama canal, there are plenty of itinerant inhabitants (maybe even a few island air pilots) hanging out under the low bridges.
Additionally, if you get hungry, you can sneak into the worlds busiest Costco and wander the aisles for a free lunch each day.
Or you could just take the light rail....... in 2030.