(1) No real discounts for HS students other than the Normal "Back to Shcool" sales which is ending. Some HSs offer a reduced pricing, but this is limited to their student only.
(2) Surcharge - quite possible, in the form of Customs and or VAT - This you could possibly check by "googling" AUS customs and VAT for your country. Do not know if AUS has a Value added Tax (VAT) the same as England.
(3) A bigger problem is finding a vender in the US that ships overseas. Could also Check Taiwan - BUT SELECT vender carefully. I'm in the US, but found my Blu-ray laptop drive at half the US price at a Taiwan site. I paid no customs (have no VAT here) and had the dive within one week.