I have checked all old coupons and price is $34.99 for Tuya WiFi Smart Home Alarm System (in Banggood). Just check coupons out (with price alert and history). Do you want to know what the best price is?
Latest coupon code price check (UTC time):
Tuya WiFi Smart Home Alarm System Security Protection Kit Wireless APP Remote Monitoring Anti-theft Alarm Doorbell Call Device Multi-functional Surveillance Kit for Home Safety Work with Alexa Google
Banggood ($34.99)
Banggood warehouse is located in China. Hmmm… There is no active coupon in Banggood at this moment. Is it good price? This is the best price in history according to CouponsFromChina database!
Link: Banggood product page
Price: $34.99
This is the best price ever noted in my database!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BG8FORMULAMX
(these codes were not working in latest coupon update, but you can check them 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
Price history (for all/most countries) for Tuya WiFi Smart Home Alarm System 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)).