Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (19.99 USD): BGcd7a51
Coupon (27.25 USD): BG589b2e
(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): BGXPJA66, BGAlerabat1, Terence, Tabby20, 2203ActiesNL, BGd9a71f, BG1efeb0, 8Couponsde, MVC8SPRING, 8BGwbg2204, tRaDetRaCKeR, 8wEbgaInS5, BGHU2108, pROMo8cuPoN, BG00c906, BGJUNXW1, BGHU2365, Cuponation9
(these coupons are old, so probably won’t work)
Price history and price alert
Price history (for all/most countries) for Xiaowei W1 300mL Wall Automatic Soap Dispenser is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).