All Aeroplanes and parts are duty free. If you buy second hand you will more than likely need a Quarantine inspection done. If you have Aircon then the gas needs to be the right type or more expense with Dpt of envionment.
20' container around 2-3000 and 40' around 4000. Add more for fees etc, about another $2-4000 depending on where in the country you are and who you use.