Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (29.99 USD): BGSDC
Coupon (35.99 USD): 12blitzw
Coupon (35.99 USD): BGANC1
Coupon (37.19 USD): aff7off
(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
There were country-specific coupon codes published on Couponsfromchina social channels and price alerts. Coupon price may vary by country, because there’re different VAT rates, shipping cost etc. There is a chance that some latest coupons are still working:
Old coupons (from the oldest to the newest): 20ANC1, 15anc1, 15bwear, 502C6B, e2bcea, BWANC1, 25BWOLF, BGss10%bw, BGGR95, BGANC1IN, BGANC1US
(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-ANC1 Noise Cancelling Wireless Earphones is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).