Bardwell F4 AIO RC Flight Controller V2 (Banggood, Aliexpress: AIO board with MPU 6000 gyro, manufactured and backed by RaceDayQuads, 1x Camera filtered power (9v);, 7.29g Weight, Betaflight OSD w/240a current sensor, Smart Audio compatibility and Camera Control capability, 9v filtered power out for VTXs – very strong filtering capability for clean video (the 5v output is also filtered), Built-in Blackbox capability, Includes vibration dampeners, 1x VTX filtered power (9v), UARTS for FRSKY, Superb board layout allowing for easy and clean builds, Power Out: 2x 5v, Compact 30.5×30.5 board layout, RX4 pads gather telemetry from each individual ESC, Centrally located gyro, 4-1 Connector utilizes the full functionality of every 4-1 ESC on the market, Programmable LED pin, 3-6s F4, SAT (2 inverted UARTS), Item name: Bardwell F4 AIO Flight Controller V2, SBUS, IBUS, 1x 3.3v, TX6 pad added so there is one additional UART for general-purpose use, Pre-flashed with BF 3.3.1 – Compatible with CLRACINGF4.hex, Joshua Bardwell authored manual and selected features, 1x VBAT, Buzzer pins, Brand name: Bardwell (the best price with coupon)).
Basically copy coupon, view price history or create e-mail price alert. Let’s see what best price is ATM.
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.
Link: Banggood product page
1. ($34.06): BGAFF10OFF
2. ($34.06): bGhOnEy10
3. ($34.06): BGdragonBoat
4. ($34.06): BgcLuBofErtA10
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 and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): bgssaff9, AFfbG10, BG12MRP, BGVDay10%off, BGSS10%SW, bgshOOp10
(probably won’t work, but you can try them out)
Price history and price alert
Check out price history chart (for all/most countries) for Bardwell F4 AIO RC Flight Controller V2. The lowest price was: $30.79.
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)).