There are a few LIBOR rates for different currencies. The rate Macquarie quoting is either USD or AUD. Most likely AUD.
Using your figure, 5.53% against 0.78% benchmark rate is NOT reasonable. This is 1000% higher. Whilest 5% sounds normal for AUD, this is very very expansive for most other major currencies.
The LIBOR rate for AUD is around 4.735% ATM. So we be paying 10% around.
http://www.interactivebrokers.com/en/p.php?f=interest
