Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (85.40 USD): BGAFF10OFF
Coupon (85.40 USD): BGTT10
Coupon (85.40 USD): bGhOnEy10
Coupon (85.40 USD): BGRC902
(CouponsFromChina.com tip: paste coupon code in your cart and click Apply 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): BGTitan, TTxBG10, BGWKF460, AFfbG10, BGF460, BG15T, 502C6B, BGVDay10%off
(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 HGLRC Titan Plus F460 RC Stack is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).