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 (161.99 USD): BGHONEY2110
Coupon (165.59 USD): BGDAVIS
(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): BG540T, BGBCFPV, BGAIRP12, Parts8, 502C6B, BGOTC20, BGBFAFF2019, BGCITYADS2019, 2020CNY, BGVDay10%off, BGMPB2020, bGhOnEy10, BGSS10%SW, bgshOOp10, BGRC902, BGTT10, BG11PP12, BGFPV-10, BGAFF10OFF, BGCuponation10
(these coupons are old, so probably won’t work)
Price history and price alert
Price history (for all/most countries) for Upgraded Edge 540T PP 15E RC Airplane Kit is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).