I think that the passenger charges are only for commercial traffic.
It's a while since I was there, but the charges were always very reasonable.
Be aware that the only thing within walking distance of the airport is a nice beach.
There is no regular public transport that I'm aware of.
There is nothing really within reasonable taxi fare distance.
Realistically you need a hire care (available at the airport). I found the best deals by calling the airport directly about a hire car, rather than the usual websites.