$8.49 – WiFi Temperature Humidity Sensor (Banggood, Aliexpress: WiFi Temperature Humidity Tester Smart Home Integration Alexa Google Assistant Mobile App Control -10 to 60℃ 0-99% Humidity (the best price with coupon)).
Use coupon and get WiFi Temperature Humidity Sensor for $8.49 (from Banggood). Price history, coupons and price alert are available on this page. What is the best price?
Latest coupon and price update (UTC):
Banggood ($8.49)
Banggood warehouse is located in China. There is no active coupon in my database right now (for Banggood). Isn’t it too expensive? Hmmm, price is higher than average (which is $7.99 right now), so better set price alert down below…
Link: Banggood product page
Price: $8.49
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/feV
Aliexpress
There’re some similar (or not) items on Aliexpress
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Price history and price alert
Here is price history (for all/most countries) for WiFi Temperature Humidity Sensor. The lowest price was: $7.49.
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)).