Aliexpress
Click here… to search for GEPRC GEP-20A-F4 AIO F4 MPU6000 Flight Controller 20A 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 (71.75 USD): BGJON8
Coupon (71.75 USD): BGRCParts8
Coupon (71.75 USD): BGToys8
Coupon (71.75 USD): BG8OFFCOUPON
Coupon (71.75 USD): TTBLACK5
(CouponsFromChina.com tip: 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
Old coupons (from the oldest to the newest): bGhOnEy10, BG20AF4, BGAFF10OFF, BGdragonBoat, BGSS10%SW, bgshOOp10, BGRC902, BgoFErTaSchInA10, BgcLuBofErtA10, BGCuponation10, BGDAVIS, BGHONEY2110, Parts8, BGGAL8, Tabby20, BG1efeb0, 8Couponsde, MVC8SPRING, 8BGwbg2204, BGJUNEGSG9, BGGutscheine
(there’s a little possibility that old coupon will work)
Price history and price alert
Do you need price history chart (for all/most countries) for GEPRC GEP-20A-F4 AIO F4 MPU6000 Flight Controller 20A? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).