Domestic and Export Sales

We have two types of sales, Domestic and Export sales for the same item. Domestic sales are packed in a less durable carton whereas the export sales are packed in a durable, costly Carton. The export sales Carton is 3$ more than the domestic carton. So currently we have two different item numbers one for domestic sales, one for export sales. Each of these have different standard costs because of the expensive Carton. What are the best practices that we can follow in order to make sure that the Carton cost is accounted for when you export the item.