Examples

Baseball bat - purchased by customer

Purchase Price USD $99.99
US Ground Shipping USD $16.00
Shipping to Australia USD $36.53 Shipped using Priority Mail
Insurance USD $4.50

The exchange rate on date of purchase was 1.0327 USD
The exchange rate on the day the bat shipped was 0.9638 USD

Costs of getting bat to US to OZ

Goods + US Ground Shipping: $115.99 USD
Exchange Rate used: Spot Rate 1.0327 - 0.025 = 1.0077
Goods + US Ground Shipping: $115.99 * (1 / 1.0077) = $115.10 AUD

Costs of shipping bat to Australia

Shipping to Australia + Insurance = $41.03 USD
Exchange Rate used: 0.9638 - 0.025 = 0.9388
Shipping + Insurance to Australia: $41.03 * (1 / 0.9388) = $43.70 AUD

US to Oz fee = $12.00 AUD

Total Cost: $115.10 + $41.03 + $12.00 = $170.80 AUD

The cost of the bat in Australia is $500.00 AUD

Savings were $329.20 AUD or 65.84%