Hi im new to dropshipping and wanted to ship electric massage gun (2kg per unit with batteries)from china to Australia .However the supplier first quoted me $37 then $40 and now $45 for epacket shipping cost per unit. She stated that the rates keep fluctuating. I just want to know if this information is aqurate and does the shipping cost fluctuate each day and what would be an aqurate estimate of the cost.

Thanks