Within Canada, I use flat rate boxes containing up to 5 kg (M=$28.75 / L=$37.95) for combined purchases. Otherwise I will find the lowest rate possible that includes tracking and insurance. The eBay listing will show a higher estimation of the shipping cost. If the actual amount is lower, the difference will be passed on to you.
To the US, I will give you the best rate I can get through eBay. As above, the eBay listing will be a higher estimation and if the actual cost is lower, the difference will be passed on to you.
If you live overseas and are interested, please just send me a message and I would be happy to calculate the shipping costs for you.
If you have any questions about the item for sale, please ask before buying.