exchange rates

Hi can someone please tell me why the exchange rates changes between sending the money and receiving it.

If i want to send AUD over to another country why does the exchange rate go down when it gets there?

any reasons?

The rate shown for the US dollar is a representative mid-point determined by the Reserve Bank on the basis of quotations in the interbank foreign exchange market at 4 pm Eastern Australian time on the day concerned.
Rates shown for most other currencies are calculated by crossing the rate for the US dollar with mid-points of buying and selling rates quoted at the same time. These rates are indications of market value only and may differ from those quoted by foreign exchange dealers.

Foreign exchange rates are subject to change at a moment's notice.
Although up-to the minute rates may be obtained by contacting a local Royal Bank branch, rates can only be guaranteed at the time the purchase or sale is conducted.
Exchange rates for cash are less favorable to recover shipping and handling charges.

Just think of money as any other goods or service. The person selling you the product (money) has to make some money to stay in business their margin is their reason for staying in business.

Cheers

Excuse my ignorance but need to clarify some basic stuff

When transfering funds to my US trading account I am given a different rate then the spot price. In some instances it can be a cent or two worse off then the days low , so why is this so? and how can I know what price I will get before I send it over?

Thanks in advance.