Just ship with UPS. With UPS you do not need your own broker. If the pearls are shipped with the airline you will have to use a broker to clear them when they reach the US. It is a hassle. It would cost about $500.
There is no import duty on the pearls as you have described them. There is export duty from Tahiti, but no import duty. There are a lot of other charges typically associated with pearl shipments coming from Tahiti. Freight is high as is insurance.
It is really strange actually. It is cheap to get pearls in and sent around the US but enormously expensive to get anything OUT of Tahiti. It is as though they don't want their precious pearls to leave
