$14.99 – Working temperature: -10°C~40°C, Product Dimensions: 62x 62x 20 (mm), Material: PC V0, Certificate: CE / FCC / Declaration of EU RoHS Conformity, Power Supply: USB 5V, Security Mechanism: WPA-PSK/WPA2-PSK, Wireless Standard: WiFi 802.11b/g/n / 433.92MHz.
The coupon price for SONOFF RF BridgeR2 Smart Wi-Fi Hub 433MHz RF is $14.99 (in Banggood). Basically copy coupon, view price history or create e-mail price alert. You probably want to know what is the best price?
Latest coupon code price check (UTC time):
Banggood ($14.99)
Banggood warehouse is located in China. I don’t think there is an active coupon right now – at least in my database. Is it cheap? It’s a good price, isn’t it? The average is $16.99.
Link: Banggood product page
Price: $14.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/i1u
Old coupons (from the oldest to the newest): BG364550, ADMITAD2212, BGSmart6, BG1382fb, MVC8SPRING, 8BGwbg2204, 2203ActiesNL, tRaDetRaCKeR, BGJUNEGSG9, BG15Sonoff, BG8ReviTrage, Cuponation9, 9OFFSUMMER
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
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
Here is price history (for all/most countries) for SONOFF RF BridgeR2 Smart Wi-Fi Hub 433MHz RF. The lowest price was: $13.99.
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)).