FS2A 4CH AFHDS 2A Receiver (Banggood, Aliexpress: 2.4G mode: AFHDS 2A, Failfe: Yes, Band width: 135, Frequency range: 2.408-2.475GHZ, Weight: 0.9 grams, Working current: 20MA, Output signal: PWM, Distance: 400+ meters, Channels: 4CH, Dimensions: 11 * 25MM, Receiver sensitivity: -92DBM, Supply voltage: 3.3-10V (the best price with coupon)).
Basically copy coupon, view price history or create e-mail price alert. What is best price?
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 price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($15.93): BGGAL8
2. ($15.93): BGRCParts8
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 and https://couponsfromchina.com/short/feV
Old coupons (from the oldest to the newest): FS2A, 20OFFRSF, Parts8, BGaDmITAd, BGCITYADS2019, 2020CNY, BGVDay10%off, BGFS12, BGFKY11, bGhOnEy10, BGTT10, BGflysky11, BGRCRR9, BG11SHOP, 13f142, BGCuponation10, BGDAVIS, BG70e5fc
(these coupons are old, so probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for FS2A 4CH AFHDS 2A Receiver. The lowest price was: $5.7.
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)).