Sorry, I'm completely lost on where to find the exchange rate...
Sorry, that's my fault. We are working on getting the WU calculator on our site, but that may be awhile and I just wanted to get the service started ASAP.
Go to westernunion.com.au and under "Calculate online money transfer" on the right, select Canada and type the amount of CAD. This will tell you the approximate fee and amount needed in AUD. So, I just tried it with 1000 CAD and it says the total with transfer including the fee would be 1110.26 AUD.
Then input this on our site to find out how many bitcoins you need to send. So at the moment in this example it would be 232.75 BTC. As I said, not the cheapest way to convert bitcoins, but I'm sure some will find it convenient.