sonic vibrating 42000 strokes per minute, 280gf.cm strong torque output, strong torque output, DuPont Tynex Brilliance bristle, improved with German Pedex brush, 3 Cleaning Modesx 4-grade Cleanness, Charging in 3.5 Hours for Full, IPX7 Waterproof Rating, Battery capacity: 2600mAh.
Basically copy coupon, view price history or create e-mail price alert. Best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($67.49): BGHONEY2110
2. ($67.49): BG10OFFAFF
3. ($73.99): 13f142
you should apply the coupon in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BGONE99, dddf57, 502C6B, vipupgrade8, bGhOnEy10, BGTMCB7, bgshOOp10, BGHB20, BgoFErTaSchInA10, BGSD58965, BgcLuBofErtA10, 7d18f7, BGHBHJ107, BGAFF10OFF, BGCuponation10
(probably won’t work, but you can try them out)
Other warehouses/versions
This item is available in 2 another warehouse/versions!
1. China – Xiaomi Oclean One Sonic Toothbrush ($-3)
2. China – Xiaomi Oclean One Sonic Toothbrush Pink ($-3)
Price history and price alert
Do you need price history chart (for all/most countries) for Xiaomi Oclean One Sonic Toothbrush Black? There we go. The lowest price was: $49.99.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).