Aliexpress
Click here… to search for Xiaomi Hey Plus Smart Bracelet Chinese Version on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. I found coupon for you. Check this out.
Link: Banggood product page
Coupon (46.32 USD): BGWRIBAND10
(CouponsFromChina.com tip: put item in your cart and apply coupon code there after clicking “Proceed to checkout”. Click to copy code and open shop)
Old coupons (from the oldest to the newest): bgsport, F8AAF1, 52ed73, ba388e, 1f6882, TTxBG10, BGKH42, BGOD1, BGkr28, AFfbG10, BGFIT8, BGMPB2020, BGAFF10OFF, bGhOnEy10, BGdragonBoat, BGSS10%SW, band10, bgshOOp10, 7d18f7, BGCuponation10
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Do you need price history chart (for all/most countries) for Xiaomi Hey Plus Smart Bracelet Chinese Version? There we go.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).