why do you charge gst on the full price and not the discounted price

[tomorrow15]

when i purchase an item in a shop i am charged gst on the discounted price not the RRP.  on EBay the gst is charged on the full price of the goods before the discount is applied.

[brerrabbit585]

If you're using a voucher to get a discount, ebay are paying part of the price to the seller.  The item is still selling for full pirce so GST has to be paid on the full price.  You can't expect ebay to pay part of the price for you and then GST on top of their portion.

[ssoronsay]

This should be irrelevant. GST is charged on what is actually paid by the purchaser so if you or the seller is discounting then the GST is on the amount paid not the amount requested. Also most is second hand and should be GST free also many OS sellers are individuals and only sell from time to time so GST would not be correct.
It seems that that the government has put GST on every sale. That is inconsistent with the regulations of GSt collection in Australia.

[lyndal1838]

The GST is charged on the total of the item price plus the postage.