I am really sorry for late reply, I tried to made a phone call to WellLink yesterday, but they just reply this morning,
However please refer the details as following ;
Normally import duty will base on CIF price, that mean cargo value + insurance+ freight charge to calculate import duty payment by HS code for each commodities, plus Thai VAT 7%.
This HS code has been applied 10% for import duty, in case that exporter could provide Thai - Asean FTA or Form D, Thai importer will pay only VAT7% and import duty would be zero.