Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. There is one great coupon!
Link: Banggood product page
Coupon (146.99 USD): 7bcdf9
(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): BGSWDKK, BGAFF7OFF, bgshOOp10, BGHome15%, BGHOMEAPP13, BGHOMEA13
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Do you need price history chart (for all/most countries) for Xiaomi SWDK K11 120W Vacuum Cleaner? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).