I have noticed that eBay seem to add extra postage charges to overseas orders?

Is this extra postage charge imposed by eBay without the sellers' consent a regular practice? Is it something that can be avoided if the seller organises postage in a different way? I think it is putting people off buying through eBay as it is pushing costs up. A recent order of mine was £10.50 for the dress plus £2.80 p&p. Unbeknown to the seller, eBay increased the postage charge to £11.00 (more than the price of the dress!). It made the purchase totally unviable which was a shame because the original costs were so reasonable.

if there is a way for sellers to avoid this extra "international shipping" charge I would like to know so I can suggest it next time I buy an item.

many thanks!