Aliexpress
Click here… to search for Xiaomi Yueli Waterproof Hair Clipper on Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. Hmmm… There is no active coupon in Banggood at this moment.
Link: Banggood product page
Price: -3 USD
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Old coupons (from the oldest to the newest): vipupgrade8, TTxBG10, 2019SPEDM, BGss506, bgssaff9, AFfbG10, BGBFAFF2019, BGCITYADS2019, Email3, BGVDay10%off, BGHOMEG12, BGAFF10OFF, bGhOnEy10, BGdragonBoat, BGSS10%SW, bgshOOp10
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Price history (for all/most countries) for Xiaomi Yueli Waterproof Hair Clipper is here.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).