Basically copy coupon, view price history or create e-mail price alert. What is best price?
Support App Tuya / Smart Life, Controller working frequency 2.4GHz WIFI, Feature 3 Kinds Of Restart State, Controller Operating Voltage “AC 100V-240V
60HZ/50HZ”, Current 16A, Model TMW02
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in Hong Kong. There are no coupons for this product 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): BG73d85c, BG9c5cca, BG299c90, ADMITAD2212, BGSmart6
(probably won’t work, but you can try them out)
Price history and price alert
Price history (for all/most countries) for Smatrul Smart Mini WiFi Light Switch Module 16A is here.
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)).