Vividwireless is offering a $50 cashback on its ViViFi Wi-Fi hotspot, making it effectively half-price. While that sounds like a good deal, you'd need to consider it carefully.
The first issue to consider is whether Vividwireless is even available in your area (it essentially only covers capital cities, and Darwin and Hobart aren't included). The second is whether its rates are competitive with other options in your region; our Planhacker guide to prepaid mobile broadband will be of assistance here.
The final issue is how comfortable you are with cashback offers, which deservedly don't have the best reputation. The deal here also requires you to have an active account for at least 35 days, which means effectively paying for at least one additional recharge before you get your money back. That would put me off, but if you're tempted by Vividwireless, it is a solid saving. The deal runs until the end of the month.