Aliexpress
Click here… to search for Xiaomi Diiib 1150mm Shower Set on 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 (243.86 USD): BGAFF10OFF
Coupon (243.86 USD): BGTT10
(CouponsFromChina.com tip: 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
Old coupons (from the oldest to the newest): AFfbG10, BGhardware, 502C6B, BGBFAFF2019, BGDH16, BG2020NS, bGhOnEy10, BGdragonBoat, bgshOOp10, BGHWDEALS, BgoFErTaSchInA10
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Price history (for all/most countries) for Xiaomi Diiib 1150mm Shower Set is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).