Aliexpress
Click here… to search for DIATONE GTR249-HD 115mm 3-4S Drone on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. There is one coupon available! Pretty cool, huh?
Link: Banggood product page
Coupon (226.90 USD): Drones6
(CouponsFromChina.com tip: put item in your cart and apply coupon code there 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): AFfbG10, BG249T, BGWKRC3, BGBFCR25, BGCITYADS2019, BGBF249T, BGBFRC6, BG249T25, BGSFD4, BGVDay10%off, BG7322, BGNTTR1, BGAFF10OFF, bGhOnEy10, BG249THD, BGdragonBoat, BGSS10%SW, bgshOOp10, BGRC902, BgoFErTaSchInA10, BgcLuBofErtA10, BG10RACING, 7bcdf9, BGMATT7, BGDAVIS
(there’s a little possibility that old coupon will work)
Price history and price alert
Here is price history (for all/most countries) for DIATONE GTR249-HD 115mm 3-4S Drone.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).