Aliexpress
Here are coupons that you can use.
Latest coupon code price check (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 USD
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
Old coupons (from the oldest to the newest): 13f142, BGAFF10OFF, BGD11043, BGB5050, BG31ae9d, ADMITAD2212, BGSmart6, MVC8SPRING, 8BGwbg2204
(there’s a little possibility that old coupon will work)
Price history and price alert
Here is price history (for all/most countries) for IMILAB ZNCZ05CM EU Smart Socket.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).