Currently a flash sale @ Gear Best
Xiaomi Smart Human Body Sensor AU$12.57
If you bundle the following with the Gateway there is also additional discount:
Xiaomi Smart Door Windows Sensor - AU$9.60 with Gateway
Xiaomi Smart Switch - AU$7.65 with Gateway
Can be had cheaper if you pay in US$ and use a credit card that doesnt charge international transaction fee like 28 degrees card.