Aliexpress
Click here… to search for Gamesir X2 Stretchable Bluetooth Game Controller on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. Only one coupon available!
Link: Banggood product page
Coupon (74.65 USD): BG717000
(CouponsFromChina.com tip: paste coupon code in your cart and click Apply 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): BG214430, BGHONEY2110, BG04dbb3, BG00ae03, BG1aa6f5, 13f142, BGb6db6d, BG8574cb, BGdeb548, BGb023eb, 00c906, BG1bf36f, BGAlerabat5, BG2a6dfe, BG904ca6, BG95f570, 2203ActiesNL, tRaDetRaCKeR, BGfe690d, BGee1115, BGVDGA07
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Here is price history (for all/most countries) for Gamesir X2 Stretchable Bluetooth Game Controller.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).