Direct power supply measurement range: DC 8-100V, Individual power supply range: DC 5-12V, Measurement range: DC 0-100V, Display format<10V, Acurancy: ±1%. Check coupons or create price alert down below. What is 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 price update (UTC time):
Banggood
Banggood warehouse is located in Hong Kong. Well, there is one coupon available right now.
Link: Banggood product page
1. ($13.15): BG00c906
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/i1u
Old coupons (from the oldest to the newest): BGRCParts8, BGJUNEGSG9, Cuponation9, 9OFFSUMMER
(there’s a little possibility that old coupon will work)
Price history and price alert
Check out price history chart (for all/most countries) for Peacefair PZEM-023 0-100V Voltage Tester. The lowest price was: $10.91.
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)).