Aliexpress
Click here… to search for Airbot Furling 32 3-6S 4x45A ESC with F3 MCU ADC Current Sensor on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (49.49 USD): BGHONEY2110
Coupon (50.59 USD): Parts8
(CouponsFromChina.com tip: coupon code has to be applied in shop’s 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): AFfbG10, affbg10, BGWKAF32, BGAF44, BGAF39, BGWK32, BGAF32, BG3241, 502C6B, BG45AESC, BG12MRP, BGAFESC, BGGEPPart, BGHJW4, BGVDay10%off, BGWKTRO, BGAFF10OFF, bGhOnEy10, BGFurling32, BGdragonBoat, BGSS10%SW, bgshOOp10, BGRC902, BgoFErTaSchInA10, BgcLuBofErtA10
(these coupons are old, so probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for Airbot Furling 32 3-6S 4x45A ESC with F3 MCU ADC Current Sensor.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).