I have checked all old coupons and price is 44.99 USD for Tuya Smart (in Banggood). You can create price alert here, copy coupons and view price history. Let’s see what best price is ATM.
Latest price update (UTC time):
Banggood (44.99 USD)
Banggood warehouse is located in China. Hmmm… There is no active coupon in Banggood at this moment. Is it a reasonable price for this item? Cool, average is 45.57 USD, so current price is lower!
Link: Banggood product page
Price: 44.99 USD
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): TTBLACK5, BG589b2e, BG45f4f7
(there’s a little possibility that old coupon will work)
Aliexpress
There’re some similar items on Aliexpress in my database. There may be some other items though.
| Image | Product (link) | Price | Coupons |
|---|---|---|---|
 |
Tuya Smart WiFi Door Sensor | 4.02 USD | – |
 |
Tuya Smart Zigbee Door Sensor | 4.63 USD | – |
 |
Tuya Smart WiFi Door Sensor | 4.87 USD | – |
 |
Tuya Smart WiFi Door Sensor | 5.10 USD | – |
 |
Tuya WiFi Switch Garage Door Controller Smart Door Opener | 10.37 USD | – |
 |
Tuya ZigBee Smart Door Sensor | 10.58 USD | – |
 |
REHENT 2.4G WiFi Smart Tuya Peephole 5000mAh Door Eye Camera | 55.95 USD | Paste “05CD03 or CDPU03 or FRCD03 or CDES03 or CDEW03 or USAFF3” (may not work) |
More on Aliexpress… Here are coupons that you can use.
Price history and price alert
Price history (for all/most countries) for Tuya Smart Door Bluetooth Lock is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).