Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. There is one great coupon!
Link: Banggood product page
Coupon (197.79 USD): BGSCM75
(CouponsFromChina.com tip: you should apply the coupon in your 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): BG9d1e13, BGdcbfa8, BG9a3058, BG8ReviTrage, Cuponation9, BGCL175
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Price history (for all/most countries) for High Pressure Cleaner 3800W 2175PSI Car Washing Machine 150Bar is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).