Price history, coupons and price alert are available on this page. Let’s see what best price is ATM.
Wireless Type Zig.Bee, Size 86*86*15.12 mm, Battery Life About 2 years, Work Temperature -5℃-50℃, Work Humidity 5%-95%RH
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. ($15.99): 13f142
just apply this code in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): Alibuy91173, 2019SPEDM, aff7off, bgssaff9, BGaDmITAd, bgchinafest, BGBFAFF2019, BGCITYADS2019, bGpAnDacHeCk, 2020CNY, BGSAMH, BGAQA15, bGhOnEy10, BGSM15, BGSMOFF, bgshOOp10
(these codes were not working in latest coupon update, but you can check them out anyway)
Other warehouses/versions
This item is available in 2 another warehouse/versions!
1. China – Xiaomi Aqara Double Smart Switch International ($-3)
2. Europe – Xiaomi Aqara Single Smart Switch International [EU] ($-3)
Price history and price alert
Check out price history chart (for all/most countries) for Xiaomi Aqara Single Smart Switch International.
Price records source(s): 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)).