Aliexpress
Click here… to search for Holybro Kakute F7 AIO STM32F745 RC Flight Controller on Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. I found coupon for you. Check this out.
Link: Banggood product page
Coupon (59.70 USD): Parts8
(CouponsFromChina.com tip: you should apply the coupon in your 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): KakuteF7AIO, 502C6B, 12parts, bgssaff9, AFfbG10, BGWKF7, BGHK7, BGKaF7, HKF7A, BG12MRP, BGHK77, BGVDay10%off, BGZHF1, BGAFF10OFF, BGKakuteF7WK, bGhOnEy10, BGHolyAIO, BGFIGN15, BGJJKL2, BGdragonBoat, BGF7AIO, BGSS10%SW, bgshOOp10, BGRC902, BGAIOHL, BgoFErTaSchInA10, BGKKJY6, BgcLuBofErtA10, BGCuponation10, BGDAVIS, BGHONEY2110
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for Holybro Kakute F7 AIO STM32F745 RC Flight Controller.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).