Aliexpress
Click here… to search for Xiaomi Mi Gaming Headset on 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 (71.99 USD): BGHALLOWEEN
Coupon (72.99 USD): Email5
Coupon (72.99 USD): BGSS10%SW
(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): aff7off, 7de541, 315c05, 502C6B, d4de0b, 6bd9bc, TTxBG10, f8aaf1, BGILstereo, BG3CSUM, bgssaff9, AFfbG10, BGBFAFF2019, BGCITYADS2019, BG20CES, BGVDay10%off, EARSP11, BGXMHH2, BGXMHAA, BGAFF10OFF, BGTT10, bGhOnEy10, bgshOOp10, BGELIG0920
(probably won’t work, but you can try them out)
Price history and price alert
Price history (for all/most countries) for Xiaomi Mi Gaming Headset is here.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).