Hey Aimee,
Not sure if this matters, but your website seems to have a little bug. Currently, you can put together a DIY Package, but it seems only the power rack attracts the 10% discount. The rest of the package is un-discounted.
Putting each item in the cart separately and then using the AUSBB code attaches the 10% discount to every item (which just saved me several hundred $$).
Not sure which of the above options are supposed to be 'allowed' or correct, but thought I should let you know.
Cheers!