Just went to post some items off and was told that for this month it's $12.50 for express post (v.s. $14.95 for regular post). Jumped online and looks like it's an Australian-wide deal. FYI, this includes tracking as well.
"Make $12.50 go further and faster than ever.
Send a 1kg Express Post parcel with next business day delivery^ for just $12.50*.
Special product offer available 1-30 September 2015."
T&CS:
*This special product offer is available in-store over the counter or online via Click and Send from 1 September 2015 to 30 September 2015. The offer must be requested in-store, specified on mailing statements using B85 for Express Post, or selected online at Click and Send. Not available via eParcel nor postage meters. Applicable where the product weighs 501 grams to 1kg and is being sent within Australia and where standard postage rates would ordinarily apply. We guarantee Express Post Saturday Delivery if you post your item on a Friday, to and within our Saturday Delivery network and meet the Express Post Saturday Delivery service conditions.
^Next business day delivery is available within the guaranteed Express Post network. For more information visit auspost.com.au/parcels-mail/express-post-parcels.html