Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. Only one coupon available!
Link: Banggood product page
Coupon (26.55 USD): Parts8
(CouponsFromChina.com tip: apply code in your basket (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): 25GR, AFfbG10, 0e7f33, FBCOUPON1, bGhOnEy10, bgshOOp10, BGRC902, BgoFErTaSchInA10, BgcLuBofErtA10, BGAFF10OFF, BGCuponation10, BGDAVIS, BGHONEY2110, BGRACING1125
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Price history (for all/most countries) for Geprc GR2306 2306 2750KV 3-5S RC Brushless Motor is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).