Dropped by around USD$3.61 since yesterday I checked. This is currently the cheapest I can find the MiBand around so far and even cheaper than the previous deal using a coupon at GearBest.
I can confirm it is a genuine Xiaomi MiBand as I have already ordered one.
Free shipping, granted it is quite slow.
Adding coupons seems to increase the price so this sale price is as good as it gets!
Also: A great modded version of the related app is found here.
It translates the app to English and allows customisable notifications so you can have the MiBand vibrate and flash customisable colours for specific notifications.
It appears that this requires Android 4.4