Aliexpress
Click here… to search for Xiaomi Huami Amazfit Stratos 2S Smartwatch on Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. I am tired of searching coupons, but I found one for you…
Link: Banggood product page
Coupon (220.49 USD): amazfit100
(CouponsFromChina.com tip: this code has to be applied in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Old coupons (from the oldest to the newest): band10, TTxBG10, Wholesale20, BG2S, BG3CSUM, BGAS2S, 502C6B, BGBFCR12
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Check out price history chart (for all/most countries) for Xiaomi Huami Amazfit Stratos 2S Smartwatch.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).