Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (24.59 USD): Terence
Coupon (24.85 USD): BG00c906
(CouponsFromChina.com tip: paste coupon code in your cart and click Apply 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): 5d0e89, VH1499, 502C6B, vipupgrade8, 1888CODE, TTxBG10, 2133CPO, BG1099HD, bgssaff9, AFfbG10, BGVH480ES, BGVDay10%off, BGHOMEG12, BGAFF10OFF, BGTT10, bGhOnEy10, BGdragonBoat, BGSS10%SW, bgshOOp10, BGHome15%, BGHOMEA15%, BgcLuBofErtA10, BGCuponation10, 13f142, BGHONEY2110, BG10OFFAFF, BGwhielabel, BGJUSE681, BGZXJU681, BG10OFFAFF1, BANGGOODSD, 00c906, BGAlerabat1
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Do you need price history chart (for all/most countries) for Xiaomi VH 480ml USB Desktop Humidifier? There we go.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).