Other Car Rental Programs/Partners (ie. Alamo, Enterprise, Sixt) - How do I pay less for only 4days?

I am trying to rent for 4 days on Hawaii's big island. I keep getting higher rates than if I put in for a week. I don't understand this. Someone suggested renting for a week and bringing it back early.. but I read about early return fees so might not be worth it.
Alamo does not charge extra to pu and d/o at different locations which is what we are doing. I checked Budget and they charge $50 .. in the end 4 days works out to be with taxes for ALamo (including a discount) 278.. seems a bit high to me.

priceline or else if you want to take advantage of enterprise coupons pm me.

priceline or else if you want to take advantage of enterprise coupons pm me.

The problem is Priceline does not allow name your own price on one ways at this location- which is what we are doing - also all the other rental companies except Alamo charge a drop off fee so even if I get a coupon or deal from another car rental company the drop off fee wipes out the discount..