You can create price alert here, copy coupons and view price history. What is the best price?
IP rating: 5ATM, Bluetooth Version: Bluetooth 5.0, Screen size: 1.39 inch, ROM: 512MB, Screen resolution: 320x 320, Waterproof / Water-Resistant: Yes, Screen: IPS, RAM: 128KB, Operating mode: Touch Screen, Model Number: Stratos 3
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 and price update (UTC):
Banggood
Banggood warehouse is located in Hong Kong. So I have checked for active coupons (all category coupons and old ones), but there was no working coupon in Banggood.
Link: Banggood product page
Price: $-3
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!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGAS3199, bgwp, BGAS3198, BGNAAFS3, BGAMZ200, BGAM3EN, amazfit100, BGABS3, BGAS3192, 7d18f7, BGA3CU, BGA3174, BGAM35, BGAS179, BGAS174, AS136, BGDQAS3, BGILAF3, BGAS139, BGPowerstation, BGAS134, BGZBAS3, BG11AS3, Email5, BGAFAMS, BGAS3U, BGBFSTR3, BGAS3BF, BGBRAS3, BGFabioamaz, 6GSGIT, BG3a5e6d
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Here is price history (for all/most countries) for Amazfit Stratos 3 Smart Watch.
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)).