Battery Voltage Sensor: 1: 10 (Scale 1100), OSD: INAV OSD w/ AT7456E chip, PPM: ST1 pad with softserial disabled, 2x Motors, Beeper: Yes, 3x LEDs for FC STATUS (Blue, Baro: BMP280 (I2C), 5x Servos outputs, Red) and 3.3V indicator(Red), IMU: MPU6000 accelerometer/gyro (SPI), Built in inverter for SBUS input (UART1-RX), VCP & 2x UARTs, RSSI: No, Blackbox: No, MCU: 100MHz STM32F411, WS2812 Led Strip: Yes, SoftSerial_Tx1: ST1 pad by default, 1x I2C.
Just check coupons out (with price alert and history). Let’s see what best price is ATM.
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. One coupon is available. Cool!
Link: Banggood product page
1. ($33.20): BGAFF10OFF
coupon code has to be applied in shop’s cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/i1u
Old coupons (from the oldest to the newest): BGUKF411, BGF411wing, AFfbG10, BGBFRCPART, 2020CNY, BGVDay10%off, bGhOnEy10, BGdragonBoat, BGRCAP10, bgshOOp10, BGRC902, BgoFErTaSchInA10, BgcLuBofErtA10, BGHONEY2110
(there’s a little possibility that old coupon will work)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – Matek Systems F411-WING STM32F411 Flight Controller [EU/UK] ($-3)
Price history and price alert
Do you need price history chart (for all/most countries) for Matek Systems F411-WING STM32F411 Flight Controller? There we go. The lowest price was: $28.99.
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)).