Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (113.39 USD): band10
Coupon (116.99 USD): BG70MAI116
(CouponsFromChina.com tip: you should apply the coupon in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Price history and price alert
Check out price history chart (for all/most countries) for Xiaomi 70mai Saphir Smart Watch.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).