Aliexpress
Click here… to search for Diatone 2018 GT-M2.506 Drone PNP on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. We have found one coupon for this product!
Link: Banggood product page
Coupon (152.99 USD): AFfbG10
(CouponsFromChina.com tip: just apply this code 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): DT149, 129DG, 502C6B, dt2506, TTxBG10, BGss9%rc, bgssaff9
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for Diatone 2018 GT-M2.506 Drone PNP.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).