Coles Barracks in Brisbane has the Optus Huawei E8372 for $9 as a clearance product. It's currently sold by Optus for $69 but as it's a clearance product the included data and sim has expired.
I've just tested and it's unlocked and works with 3G 900/2100MHz and 4G 700/1800/2300/2600MHz
It also comes with a Sim card inside but mine has an expiry date of 1 July 2016 so she also gave me a $2 starter sim included.
They've also got several more of the older 3G Pocket Hotspot also at $9.
Included in Modem + Mobile Phone Clearance @ Coles (North Lakes, QLD) (but not in title - so a valid deal) - handy reference of other models on sale.
This old 4G modem is the pick of models on clearance!
Unless you need to use Optus, Probably better to buy the Telstra 4GX USB WiFi modem for same price when on special, comes with 3GB data & can be unlocked free. Just lacks car charger ($14 next week)
Saw other $9 modems (eg MF65 wifi 3G modem) at a Brisbane Coles yesterday, so expect clearance may be available at other Coles. MF65 has sold far cheaper & included 2GB data.
The other modems are being cleared as are old, slow 3G models with expired data.