Latest update shows that Tuya Bluetooth Smart Thermometer Humidity Sensor costs $10.99 (in Banggood). Go down and check coupons out. Remember to check price history if it is available. Let’s see what best price is ATM.
Tuya bluetooth Smart LCD Screen Digital Thermometer Temperature Humidity Sensor Moisture Meter App Remote Control
Latest coupon code price check (UTC time):
Banggood ($10.99)
Banggood warehouse is located in China. So I have checked for active coupons (all category coupons and old ones), but there was no working coupon in Banggood. Is it a low price? From what I can see this price is higher than average price ($9.66).
Link: Banggood product page
Price: $10.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BG5b59df
(there’s a little possibility that old coupon will work)
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
Here is price history (for all/most countries) for Tuya Bluetooth Smart Thermometer Humidity Sensor.
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)).