$18.99 – that is current price with coupon for Smart Tuya WiFi Temperature Controller Thermostat (in Banggood). Go down and check coupons out. Remember to check price history if it is available. Do you want to know what the best price is?
Smart Tuya WiFi Temperature Controller Thermostat Intelligent Floor Heating Constant Temperature Switch Programmable Room Temperature Controller Hydropower Boiler Temperature Control Socket
Latest coupon code price check (UTC time):
Banggood ($18.99)
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. Price? It looks like it’s a good price (lower than average ($20.59)).
Link: Banggood product page
Price: $18.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGROCTIFWI, BGa1bdde
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – Smart Tuya WiFi Temperature Controller Thermostat [EU] ($18.99)
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
Check out price history chart (for all/most countries) for Smart Tuya WiFi Temperature Controller Thermostat.
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)).