International postage

[rubikon]

I have stamps for collectors for sale, usually Buy it Now format. I have been charging $0.50 for postage. I don't have a lot of sales, but they are from the United States. I can modify the postage for multiple orders if the customer uses Add to Cart and then requests an invoice. This does not involve a lot of weight: most under one ounce, two at  most.

I have a request from an Australian for a set of stamps. Global postage is $1.15. What is the easiest way to generate an invoice? Buy It Now will finalize the sale with $0.50. I suggested to use the Cart method. 

Just wondering, is that ok or is there an easier method?

Thanks,

Don  (rubikon)