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 great coupon!
Link: Banggood product page
Coupon (113.39 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): QX7FR, 502C6B, 99.99X71, DRONEPL1, FSQX7, esQX7, 12QX7, FrskyQx7, 12qx7, d8f2bb, TTxBG10, QX7105, dronians01, 10Frsky, BGQX7, BGQX7E, BGPAYPALSS, BGaDmITAd, BGX7HK, BGQX795, BGBINKUPON7822, BGBFAFF2019, BGCITYADS2019, 7bcdf9, Parts8, BGX7NY, 2020CNY, BGVDay10%off, BGX718, BGX7USA, BGX7SP, BGQX7US, BGGRHSK8, BGX7M7, BGQX7WK, BGSS10%SW, BGSPR02, BGX7SP19, BGX7FR, BGRRFC1, bgshOOp10, BGFK11, BGX7DQ, BGX7SPST
(these coupons are old, so probably won’t work)
Price history and price alert
Price history (for all/most countries) for FrSky TARANIS Q X7 RC Transmitter White is here.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).