It's not Ebay who are paying the taxes it is every seller whether they are in NSW Australia and sell it to someone in Australia they are paying the GST to Ebay

You may  havepaid  GST on the item when you first purchased it  and then when you want toget ridofitonEbay are paying GST again onyourfinal feeand listingfee - listing used to be $1.50 - it is now $1.65 (GST added)