Price history, coupons and price alert are available on this page. Let’s see what best price is ATM.
KV: 3500KV, Configuration: 9N 12P, Shaft Diameter: 2mm, Stator Diameter: 14mm, Compatible Propeller Sizes: 3 inch
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($14.55): Cuponation9
2. ($14.71): TTSUMMER8
just apply this code in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): TTxBG10, BGGR1408, BGGEPDrone, BGGEPPart, Parts8, AFfbG10, BGMPB2020, BGAFF10OFF, bGhOnEy10, BG1408EDX, BGdragonBoat, BGSS10%SW, bgshOOp10, BGRC902, BgoFErTaSchInA10, BgcLuBofErtA10, BGCuponation10, BGDAVIS, BGHONEY2110, BGGAL8, BGJON8, BGRCParts8, Tabby20, BG1efeb0, 8Couponsde, MVC8SPRING, 8BGwbg2204, tRaDetRaCKeR, 8wEbgaInS5, pROMo8cuPoN, BG8RCToy, BGJUNEGSG9, BGRCT10
(these coupons are old, so probably won’t work)
Price history and price alert
Check out price history chart (for all/most countries) for GEPRC GEP-GR1408 Brushless Motor 3500KV.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).