Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. Well, there is one coupon available right now.
Link: Banggood product page
Coupon (148.82 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
There were country-specific coupon codes published on Couponsfromchina social channels and price alerts. Coupon price may vary by country, because there’re different VAT rates, shipping cost etc. There is a chance that some latest coupons are still working:
Old coupons (from the oldest to the newest): faa3f9, quad35, AFfbG10, BGS620, BGS654, BGAFF10OFF, BGS6DS, BGab0751, BGe5eaea, BG9d5ddd, BG537736, BG147338, BG0c6649
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Price history (for all/most countries) for Wingsland S6 Drone with 2 Batteries is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).