Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. Only one coupon available!
Link: Banggood product page
Coupon (117.25 USD): 00c906
(CouponsFromChina.com tip: apply code in your basket (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): Email5, BGDMCM13, BGHCLE15, BGDMCM3, bgshOOp10, BGCNDM3, BGHome15%, BGHOMEAPP13, BGHOMEA13, BG11SHOP, 13f142, BG10OFFAFF, BGwhielabel, 7bcdf9, BG10OFFAFF1, BANGGOODSD
(probably won’t work, but you can try them out)
Price history and price alert
Here is price history (for all/most countries) for Deerma CM1300 Anti-Mites Vacuum Cleaner.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).