Price history, coupons and price alert are available on this page. What is best price?
Working range: 3 – 7.5 V, 0 – 3 A, Resolution: 10mV, 1mA, Error: Voltage less than + / – 1pct, current less than + / – 2pct, Full range voltage drop: 200mV (current detecting)
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 code price check (UTC time):
Banggood
Banggood warehouse is located in China. Only one coupon available!
Link: Banggood product page
1. ($2.35): BGAFF10OFF
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
Old coupons (from the oldest to the newest): e2bcea, TTxBG10, 2019SPEDM, bgssaff9, AFfbG10, 502C6B, BGBFAFF2019, BGCITYADS2019, BGMPB2020, bGhOnEy10
(there’s a little possibility that old coupon will work)
Price history and price alert
Price history (for all/most countries) for KW201 USB Power Current Voltage Tester is here.
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)).