$10.99 – SONOFF MINI R4 Wifi Switch Module (Banggood, Aliexpress: SONOFF MINI R4 Wifi Switch Module Smart Wi-Fi Two Way Switch Smart Home Works R5 S-MATE Wireless Control Alexa Google Home (the best price with coupon)).
You can get SONOFF MINI R4 Wifi Switch Module for $10.99 using coupon code (in Banggood). You can create price alert here, copy coupons and view price history. You probably want to know what is the best price?
Latest price update (UTC time):
Banggood ($10.99)
Banggood warehouse is located in China. I’m afraid that there’s no working coupon in Banggood. Is it good price? This price is higher than average price ($10.09) for this item.
Link: Banggood product page
Price: $10.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
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 MINI R4 Wifi Switch Module? There we go. The lowest price was: $9.19.
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)).