You can create price alert here, copy coupons and view price history. Let’s see what best price is ATM.
Humidity measurement accuracy: +/-%3RH, Power consumption: 350uA, Temperature measurement accuracy: +/-0.5C, Temperature measurement: -40C-80C, Size: 40*40*18mm, Power supply: 3.1-5.5V, Humidity measurement: 0-99.9%, Humidity resolution: 0.1%RH, Temperature resolution: 0.1%C
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in Europe 
. I can’t find any active coupons for this product in Banggood. There’s only 1 record in my database, so I have no idea if the price is OK.
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Price history and price alert
It’s a new item in our database, so I can’t create price history chart. We have saved this price in database: $2.99.
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)).