Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. One coupon is available. Cool!
Link: Banggood product page
Coupon (12.87 USD): Parts8
(CouponsFromChina.com tip: apply it 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): hg1407, 502C6B, TTxBG10, BG1407, BGfl1407, bgssaff9, AFfbG10, BGWKHF1407, BGCITYADS2019, BGVDay10%off, bGhOnEy10, BGdragonBoat, BGSS10%SW, bgshOOp10, BGRC902, BgoFErTaSchInA10, BgcLuBofErtA10, BGAFF10OFF, BGCuponation10, BGDAVIS, BGHONEY2110
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Do you need price history chart (for all/most countries) for HGLRC Flame 1407 3600KV 3-4S RC Motor? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).