UNI-T UT658B USB Tester (Banggood, Aliexpress: Current Monitoring Accuracy ±(1%+5), Input Voltage Range (V) 3V-9.0V, Voltage Resolution 0.01V, Capacity Data Storage 10 Group, FCC, Warning Higher than 5.3V lower than 4.7V, Working Temperature -10℃-40℃, Relative Humidity <75%, Capacity 0-39999mAh, Current Monitoring Range (A) 0A-3.5A, ROHS, Lead Length 10cm, Display Way LCD Backlight, Storage Temperature -10℃-50℃, Voltage Monitoring Accuracy ±(1%+5), Current Resolution 0.01A, Certification CE (the best price with coupon)).
Just check coupons out (with price alert and history). You probably want to know what is the best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
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. Only one coupon available!
Link: Banggood product page
1. ($13.74): BGherra
apply code in your basket (cart) after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/feV
Old coupons (from the oldest to the newest): 15ANENG, AFfbG10, BGVDay10%off, BGAFF10OFF, BGTT10, bGhOnEy10
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Price history (for all/most countries) for UNI-T UT658B USB Tester is here. The lowest price was: $6.01.
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)).