You can create price alert here, copy coupons and view price history. You probably want to know what is the best price?
Max Current: 50A, Color: Yellow, High rate PWM: 8K, Original box: NO, Ni-Mh/Ni-cd: 4-10Ni- MH, BEC: 3A / 5V (Switch), Net Weight: 28g, Size: 45mmx 26mmx 10mm, Package weight: 37g, Li-Poly: 2-3, DC: 3.7V-14.8V, Net weight: 31g
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. Only one coupon available!
Link: Banggood product page
1. ($8.97): BG589b2e
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 and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): ADMITAD2212, 2022ACTIESNL, Terence, Tabby20, 8Couponsde, MVC8SPRING, 2203ActiesNL, BG00c906, BGJUNEGSG9, Cuponation9, 9OFFSUMMER
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Check out price history chart (for all/most countries) for XXD HW40A 40A Brushless Motor ESC.
Price records source(s): 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)).