Go down and check coupons out. Remember to check price history if it is available. Best price?
1x SONOFF® G1 16A GPRS Remote Control Switch GSM Mobile Phone App Remote Controller Module
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. You can get coupon down below.
Link: Banggood product page
1. ($20.66): elec
paste coupon code in your cart and click Apply after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Price history and price alert
Do you need price history chart (for all/most countries) for SONOFF G1 GPRS Remote Control Switch? There we go.
Price records source(s): Gearbest, 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)).