Aliexpress
Click here… to search for Hubsan H216A X4 Desire Pro on Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. I can’t find any active coupons for this product in Banggood.
Link: Banggood product page
Price: -3 USD
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Old coupons (from the oldest to the newest): 40b15f, 502C6B, TTxBG10, AFfbG10, bGhOnEy10, BGRCH216A, bgshOOp10
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Here is price history (for all/most countries) for Hubsan H216A X4 Desire Pro.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).