$20.99 – Smart Tuya Zigbe WIFI Airbox CO2 Formaldehyde VOC Detector Temperature Humidity Sensor App Control Smart Home Scene Linkage Work with Amazon Google Assistant – Zigbee.
Latest update shows that Smart Tuya Zigbee WIFI Airbox CO2 Formaldehyde VOC Detector costs $20.99 (in Banggood). You can create price alert here, copy coupons and view price history. Let’s see what best price is ATM.
Latest price update (UTC time):
Banggood ($20.99)
Banggood warehouse is located in China. As you can see I didn’t find any active coupon for this product right now… Well, is it a good price anyway? Wow! That’s the lowest price in CouponsFromChina database!
Link: Banggood product page
Price: $20.99
Additional Banggood coupons: first page and second page
This is the best price ever noted in my database!
Old coupons (from the oldest to the newest): BG977107
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
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 Smart Tuya Zigbee WIFI Airbox CO2 Formaldehyde VOC Detector is here. The lowest price was: $20.99.
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)).