Where the importer buys the international transport from a freight forwarder who subcontracts that transport to a third party, which amount is included in the value of the taxable importation?

Is it the amount paid by the importer to the freight forwarder or the amount paid by the freight forwarder to the third party?

The value of the taxable importation includes the amount paid or payable by the person making the taxable importation (the importer). An amount paid by a service-provider to a third party is not relevant.