Xiaomi Grey Digital Door Lock (Banggood, Aliexpress: security door, Material: Stainless Steel, Length of Password: 6 Letters, Size: 365MM*164MM*84MM, Emergency Power Supply: Micro USB, Work temperature: -25~65℃, Fit for: Wooden Door, Thickness of the door: 45-120MM, Product Size: 362MM*75MM*26MM (the best price with coupon)).
You can create price alert here, copy coupons and view price history. What is best price?
Aliexpress
I could not find it on Aliexpress. Click here to search by yourself.
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($117.59): BG2020NS
2. ($124.51): AFfbG10
put item in your cart and apply coupon code there after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/feV
Old coupons (from the oldest to the newest): Xiaomi001, BGBFAFF2019, BGBF001
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Check out price history chart (for all/most countries) for Xiaomi Grey Digital Door Lock. The lowest price was: $106.39.
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)).