You can get 100A Digital for 17.99 USD with coupon (from Banggood). Go down and check coupons out. Remember to check price history if it is available. You probably want to know what is the best price?
Latest price update (UTC time):
Banggood (17.99 USD)
Banggood warehouse is located in China. Too bad there’s no coupon right now in Banggood. You probably want to know if this is a good price. The average price for this item is 18.49 USD, so I think it’s a good price!
Link: Banggood product page
Price: 17.99 USD
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BG20236Tool
(these codes were not working in latest coupon update, but you can check them out anyway)
Aliexpress
Click here… to search for AC40V-300V 100A Digital Single Phase Energy Meter on Aliexpress
Here are coupons that you can use.
Price history and price alert
Here is price history (for all/most countries) for AC40V-300V 100A Digital Single Phase Energy Meter.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).