Aliexpress
Click here… to search for URUAV UE2 40A RC ESC on Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. You can get coupon down below.
Link: Banggood product page
Coupon (22.13 USD): AFfbG10
(CouponsFromChina.com tip: put item in your cart and apply coupon code there 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): 502C6B, 28RC, TTxBG10
(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 URUAV UE2 40A RC ESC is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).