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 (98.99 USD): AFfbG10
Coupon (98.99 USD): BGBFCR25
(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): R90P, TTxBG10, BGR90P, 2019SPEDM, 10rcdrones, BGR239P, 502C6B, BG11R90
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Check out price history chart (for all/most countries) for Diatone 2019 GT R239 R90 Pink Drone PNP.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).