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 (12.97 USD): BGAFF10OFF
Coupon (12.97 USD): bGhOnEy10
(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): 12blitzw, e2bcea, 15BW, BGss10%bw, AFfbG10, 502C6B, BGVDay10%off
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Price history (for all/most countries) for BlitzWolf BW-ES1 Graphene Earphones is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).