Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (242.27 USD): BG1efeb0
Coupon (244.91 USD): Terence
Coupon (244.91 USD): 2203ActiesNL
Coupon (247.54 USD): BG00c906
(CouponsFromChina.com tip: apply it 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): BGJP20669, BGOxy10, BGJP2066, BGJP20661, BGd0b05d, 00c906, ADMITAD2212, 2022ACTIESNL, Tabby20
(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 1-2L Portable Oxygen Concentrator Generator is here.
Price records source(s): Banggood
Click on image to enlarge.
You can set price alert (for Banggood).