Just check coupons out (with price alert and history). Best price?
Sterilization Method: UV Light Irradiation, Brand: Daewoo, Gear Adjustment: 2gear, Voltage: 220V, Battery Capacity: 2200mAh, Working Time: 25/14min, Color: White/Purple, Vacuum Degree: 8000Pa, Beating Frequency: 8000 times/minute, Charging Time: about 3.5h, Power: 100W, Model: V1, Battery Type: Li-ion battery
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. I’m afraid that there’s no working coupon in Banggood.
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGHOMEA13, 7bcdf9, BGCNDEAV, BG10OFFAFF, BGwhielabel, BG10OFFAFF1, BANGGOODSD
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Here is price history (for all/most countries) for Daewoo V1 UV Sterilization Mattress Vacuum Cleaner.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).