The shipping address is domestic to those locations, you only need pay the amount in the checkout. Additional customs clearance charges related to the value of the goods, would covered in the DDP (Delivery Duty Paid) basis which means that all relevant import taxes and duties are included in the final purchase price.
Taxes and duties are calculated according to your shipping destination customers in Australia and Singapore will be charges the standard local taxes as shown in checkout.
The Australia centre primarily services domestic and New Zealand shipments and the Singapore centre primarily services domestic and South East Asia. Orders placed via our South East Asia sites (excluding Singapore) will be shipped DDU (Delivery Duty Unpaid). Once your order arrives at its destination, you may be required to pay import duties, customs and local sales taxes levied by the country you are shipping to.