Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. There is one coupon right now! Check this out.
Link: Banggood product page
Coupon (12.74 USD): Parts8
(CouponsFromChina.com tip: apply it 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): 2020CNY, BGVDay10%off, BGTT10, bGhOnEy10, BGSS10%SW, BGRCRR9, BGRC902, BG11SHOP, BGDAVIS, 13f142, BGradio9
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Check out price history chart (for all/most countries) for LANTIAN 2.4G T-Style RC Antenna for Frsky Taranis X-lite.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).