Product: Mi Multifunctional Digital Clock, Material: PC+ABS+PMMA, Package size: Approx. 16*8.5*1.5cm/6.30*3.35*0.59in, Product size: Approx. 11*5.5*1.01cm/4.33*2.17*0.40in, Battery: 2 * CR2032, Humidity Test Range: 0% RH – 99% RH, Temperature Test Range: 0-60 degrees, Working Voltage: DC2.5V-3V, BT Version: 4.0, Color: White.
Price history, coupons and price alert are available on this page. Best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
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 China. One coupon is available. Cool!
Link: Banggood product page
1. ($15.12): vipupgrade8
you should apply the coupon in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): ML15%Pro, BG0709
(these coupons are old, so probably won’t work)
Price history and price alert
Check out price history chart (for all/most countries) for Xiaomi Mijia Digital ClockTemperature Humidity. The lowest price was: $13.99.
Price records source(s): Gearbest, 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)).