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 (78.02 USD): elec
Coupon (78.02 USD): BGAFF10OFF
Coupon (78.02 USD): bGhOnEy10
(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): 2019SPEDM, AFfbG10, 502C6B, BGBFAFF2019, BGCITYADS2019, BGE13, BGAMEPAD, BGVDay10%off, BGMPB2020
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Price history and price alert
Price history (for all/most countries) for Gamesir M2 Gamepad is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).