Aliexpress
Click here… to search for Aromatherapy 6pcs 10ml Organic Essential Oil for Diffusers [EU] on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in Europe 
. This is new product in my database, so I don’t know if this price is good.
Link: Banggood product page
Coupon (11.89 USD): BG75597c
Coupon (12.73 USD): Cuponation9
Coupon (13.15 USD): BG00c906
(CouponsFromChina.com tip: put item in your cart and apply coupon code there 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): BGGRFE231, BGHB218, 2203ActiesNL, tRaDetRaCKeR, BGHECARE1, BG4ee866
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Not enough data to show price history chart… 7.19 USD is the only recorded price. It was not cheaper than that since we have saved it in DB.
You can set price alert (for Banggood).