Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. Only one coupon available!
Link: Banggood product page
Coupon (16.79 USD): BGAudio9
(CouponsFromChina.com tip: just apply this code 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): BG487be0, BGAudio3
(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 SX960 2.4G Wireless Collar Clip Microphone is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).