$21.99 – FMS Reflex V3 Stable Flight Controller Integrated bluetooth for RC Airplane.
You can get FMS Reflex V3 Stable Flight Controller for $21.99 with coupon (from Banggood). Just check coupons out (with price alert and history). You probably want to know what is the best price?
Latest price update (UTC time):
Banggood ($21.99)
Banggood warehouse is located in China. I think you want to know if the price is good. Well, according to CouponsFromChina database this price is the best in history (2 records). I found coupon for you. Check this out.
Link: Banggood product page
Price without coupon: $26.99
1. ($21.99): BGb353d3
apply code in your basket (cart) after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
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.
Price history and price alert
Price history (for all/most countries) for FMS Reflex V3 Stable Flight Controller is here. The lowest price was: $21.99.
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)).