CIF means "cost, insurance and freight." It is an important calculation because this is the dutiable amount that customs will use. Meaning, if your item costs $100 to purchase, $15 to ship to the BVI, and $2 of insurance, the duty rate will be applied to $117, not just the $100 of value.
CIF Value =
Package's invoice value +
Freight cost (according to Customs) +