Aliexpress
Click here… to search for 12Pcs Replacement Parts for Eufy 11S RoboVac 30 Vacuum Cleaner [EU] on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in Europe 
. Uhm… There’s no price history (in my database) for this product right now. There is one great coupon!
Link: Banggood product page
Coupon (9.39 USD): BG589b2e
(CouponsFromChina.com tip: apply code in your basket (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): BG2bbacc, Cuponation9, BGAHPU13, BGeaf456, BG00c906
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
It doesn’t make sense to generate price history chart, because there is one price record which is: 6.99 USD.
You can set price alert (for Banggood).