Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. I found coupon for you. Check this out.
Link: Banggood product page
Coupon (389.07 USD): BGHONEY2110
(CouponsFromChina.com tip: coupon code has to be applied in shop’s 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): BGPOD1B, BGDDKJ1111, BgcLuBofErtA10, BGDDKJ11, BGAFF10OFF
(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 DEDAKJ DDT-1B 100W Power Oxygen Generator 1-6L.
Price records source(s): Banggood
Click on image to enlarge.
You can set price alert (for Banggood).