Aliexpress
There’re some similar items on Aliexpress in my database. There may be some other items though.
| Image | Product (link) | Price | Coupons |
|---|---|---|---|
 |
Xiaomi Youpin Deerma DEM-CS10M Mini Dehumidifier | 32.29 USD | – |
 |
Xiaomi Deerma 350mL Smart Water Bottle | 43.04 USD | – |
More on Aliexpress…Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (29.18 USD): BGDEER05
Coupon (31.19 USD): PICODICOM
(CouponsFromChina.com tip: coupon code has to be applied in shop’s cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): 502C6B, 919c60
(these coupons are old, so probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for Xiaomi Deerma DEM-F420 4L Air Humidifier.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).