According to my DB the lowest price is $37.95 for BSIDE S30 Smart Multimeter (in Banggood). Price history, coupons and price alert are available on this page. Do you want to know what the best price is?
Latest price update (UTC time):
BSIDE S30 Smart Multimeter with Infrared Temperature Measurement Color Screen High Precision Voltage Current Resistance Capacitance Tester
Banggood ($37.95)
Banggood warehouse is located in China. I have no active coupons for you right now. Isn’t it too expensive? Maybe there’re no more promotions for this item, because current price is higher than average (which is equal $32.87)
Link: Banggood product page
Price: $37.95
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
There were country-specific coupon codes published on Couponsfromchina social channels and price alerts. Coupon price may vary by country, because there’re different VAT rates, shipping cost etc. There is a chance that some latest coupons are still working:
1. (9.9.2024, $29.99): BG3622f6
Item: BSIDE S30 Smart Multimeter
Countries: France
Old coupons (from the oldest to the newest): BGTOOS729, BG8FORMULAMX, BGb91ed9, BG6f44d3
(I don’t think these’re gonna work, but you can try ’em out anyway)
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
Price history (for all/most countries) for BSIDE S30 Smart Multimeter is here.
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)).