Aliexpress
Click here… to search for GameSir G4s Gamepad 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 (38.18 USD): elec
Coupon (38.18 USD): BGAFF10OFF
Coupon (38.18 USD): BGTT10
Coupon (38.18 USD): bGhOnEy10
(CouponsFromChina.com tip: coupon code has to be applied in shop’s 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): 20eb83, 502C6B, e2bcea, AFfbG10, f3ee93, BGE13, BGAMEPAD, BGVDay10%off
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Price history (for all/most countries) for GameSir G4s Gamepad is here.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).