Confusion when living in the states and buying parts from Australia

You will simply need to pay via credit card or PayPal, the conversion will be calculated at the time of transaction based on the exchange rate at that time for the type of card being used. You will only pay AUD1850 but be debited the USD equivalent (circa USD1200) according to this exchange rate. This form of payment / conversion / debit is what we Australians go through on a daily basis when purchasing parts from the USA.