Right now the best price with coupon code for SONOFF Zigbee 3.0 USB Dongle E ZB USB With Antenna Gateway Analyzer is $22.99 (in Banggood). Basically copy coupon, view price history or create e-mail price alert. What is best price?
Latest price update (UTC time):
Can use ZHA in Home Assistant or use Zigbe2MQTT, SMA interface external antenna, 20dBm output gain, Base on TI CC2652P CP2102N, Pre-flashed with Z-Stack 3.x.0 coordinator firmware, Optional 1.5m USB extension cable for better signal range, Aluminum housing effectively reduces signa1 interference from peripherals
Banggood ($22.99)
Banggood warehouse is located in China. There are no coupons available at this moment in Banggood. Is it good price? Hmmm, price is higher than average (which is $22.90 right now), so better set price alert down below…
Link: Banggood product page
Price: $22.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): Cuponation9, BG8ReviTrage
(you can check these old coupons out, but these probably won’t work)
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Do you need price history chart (for all/most countries) for SONOFF Zigbee 3.0 USB Dongle E ZB USB With Antenna Gateway Analyzer? There we go.
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)).