Basically copy coupon, view price history or create e-mail price alert. Do you want to know what the best price is?
Bluetooth 4.0 chip, IP67 waterproof, Built-in chip type: NRF52832, Battery Capacity: 320mAh, Standby time: 6 months
Aliexpress
There’re some similar (or not) items on Aliexpress
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. Well, there is one coupon available right now.
Link: Banggood product page
1. ($71.99): band10
apply code in your basket (cart) after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): mijia13, mijia12, EU1911418, 502C6B, e2bcea, TTxBG10, aff7off, 2019SPEDM, BG3CSUM, BGMJQWGR, BGMIJIAW, AFfbG10, BGMJQW, BGSYB01, BGBFAFF2019, BGXMMJQW, BGVDay10%off, BGBGAFF10OFF, BGMJ49, bgshOOp10
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Other warehouses/versions
This item is available in 2 another warehouse/versions!
1. China – Xiaomi Mijia SYB01 Smartwatch Black ($-3)
2. China – Xiaomi Mijia SYB01 Smartwatch Blue ($-3)
Price history and price alert
Check out price history chart (for all/most countries) for Xiaomi Mijia Smartwatch Dark Gray.
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)).