Aliexpress
Click here… to search for Oxygen Concentrator DEDAKJ DE-2SW 2L-9L [EU] on Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in Europe 
. I’m not sure about the price, coz I have only 1 record(s) in my database. You can get coupon down below.
Link: Banggood product page
Coupon (274.15 USD): 8BGwbg2204
(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
Price history and price alert
It doesn’t make sense to generate price history chart, because there is one price record which is: 246.99 USD.
You can set price alert (for Banggood).