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 (836.10 USD): bGhOnEy10
Coupon (836.10 USD): BGdragonBoat
Coupon (836.10 USD): BgcLuBofErtA10
(CouponsFromChina.com tip: you should apply the coupon 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): BGDC2SET, BGSS10%SW, BGDC2P, bgshOOp10, BGRC902, BgoFErTaSchInA10
(these coupons are old, so probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for iFlight TITAN DC2 HD 122mm 4S BNF With DJI Digital Air Unit and Goggles.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).