Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (10.79 USD): BGRADIORU
Coupon (11.03 USD): BGRCParts8
(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): aff7off, rchobbies8, TTxBG10, e2bcea, 502C6B, d8f2bb, Parts8, BGaDmITAd, BGBFAFF2019, BG9NY, 2020CNY, BGVDay10%off, BGFS12, BGFKY11, bGhOnEy10, BGflysky11, BGRCRR9, BGAFF10OFF, BG11SHOP, BGDAVIS, 13f142, BGradio9, BG70e5fc, BGGAL8, BG1efeb0, 8Couponsde, MVC8SPRING, 8BGwbg2204, tRaDetRaCKeR, 8wEbgaInS5, pROMo8cuPoN, BG8RCToy, BGJUNEGSG9, BGRCT10
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Do you need price history chart (for all/most countries) for FlySky RC Data Cable FS-i6 FS-T6? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).