Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. Only one coupon available!
Link: Banggood product page
Coupon (78.21 USD): BG10OFFAFF1
(CouponsFromChina.com tip: this code has to be applied 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): 7d18f7, BGCNDERM3, BGHOMEA13, BGCNDERCM3, 13f142, BG10OFFAFF, BGwhielabel
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Check out price history chart (for all/most countries) for Deerma CM300 Anti-Mites Vacuum Cleaner.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).