Use coupon and get Tuya Smart Zigbee 3.0 for 20.54 USD (from Banggood). Just check coupons out (with price alert and history). You probably want to know what is the best price?
Latest coupon code price check (UTC time):
Banggood (20.54 USD)
Banggood warehouse is located in China. I’m afraid that there’s no working coupon in Banggood. You probably want to know if this is a good price. Hmmm, price is higher than average (which is 18.49 USD right now), so better set price alert down below…
Link: Banggood product page
Price: 20.54 USD
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Aliexpress
Here are coupons that you can use.
Price history and price alert
Price history (for all/most countries) for MoesHouse ZS-B-US Tuya Smart Zigbee 3.0 Light Switch is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).