I have just checked coupons. The lowest price I could get is $25.99 for FNIRSI S1 Digital Multimeter (in Banggood). You can create price alert here, copy coupons and view price history. You probably want to know what is the best price?
FNIRSI-S1 9999 Counts Digital Multimeter AC DC Voltage Resistance Capacitance Diode NCV Hertz Live Wire Tester with Thermocouple
Latest coupon and price update (UTC):
Banggood ($25.99)
Banggood warehouse is located in China. Coupons for FNIRSI S1 Digital Multimeter? Nope, there’re no coupons in Banggood. You probably want to know if this is a good price. IMHO this is a good price, coz it’s lower than average ($26.99)
Link: Banggood product page
Price: $25.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGM1TOOLS88, BG20236Tool, BGTOOS729
(these coupons are old, so probably won’t work)
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
Check out price history chart (for all/most countries) for FNIRSI S1 Digital Multimeter.
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)).