Well it's the start of December 2018 and this practice is still going on. If the seller chooses the Global shipping program (does not seem to happen with US post etc ) you get charged more than 10% on your item. Basically they are using this as an excuse to simply exploit Australian customers. I have contacted Ebay and it seems that most of the employees I have talked to seem to have a problem with calculating what 10% of an item plus shipping is. I think the best way to deal with this it by Australian Government Consumer protection channels , then make Ebay or the shipper they use refund all of the money they should not have charged in the first place..
Such a simple thing to fix, seems so hard for Ebay to sort out. Then again, maybe ebay is making a profit from this exploitation???
