ATM you can buy Atorch Tuya AC50-320V Smart Life Din Rail WIFI Smart Energy Meter for $20.99 (in Banggood). Basically copy coupon, view price history or create e-mail price alert. Best price?
GR2PW AC50-320V 100A Smart Electricity Meter Tuya WiFi Din Rail Power Energy Meter Digital Display Monitor Voltage Curve Ammeter
Latest coupon code price check (UTC time):
Banggood ($20.99)
Banggood warehouse is located in China. Hmmm… There is no active coupon in Banggood at this moment. Is it expensive? Hmmm, price is higher than average (which is $18.47 right now), so better set price alert down below…
Link: Banggood product page
Price: $20.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGcac934
(I don’t think these’re gonna work, but you can try ’em out anyway)
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Do you need price history chart (for all/most countries) for Atorch Tuya AC50-320V Smart Life Din Rail WIFI Smart Energy Meter? There we go.
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)).