Just an update - there's now also www.bookdepository.com, which somethimes has even better prices than bookdepository.co.uk owing to our relative strength against the $US. For example, Transformers Exodus:

$34.78AU http://www.bookdepository.co.uk/book...6/Transformers

$22.78AU http://www.bookdepository.com/book/9...6/Transformers