0.28 Inch 2.5V-30V Mini Digital Volt Meter (Banggood, Aliexpress: Display: 0.28 inch LED, Measurement rate: ≥200mS / times, Red line is the input positive, Working current: <30mA, Installation hole: 23 × 10 mm, Black line is the input negative, Detection voltage: DC2.5V ~ 30V, Accuracy: 1% (+/- 1 word), Dimensions: 31 × 12.0 × 9mm (lengthx widthx height) (the best price with coupon)).
Basically copy coupon, view price history or create e-mail price alert. Let’s see what best price is ATM.
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. Only one coupon available!
Link: Banggood product page
1. ($7.56): BG00c906
just apply this code in your 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/5cd
Price history and price alert
Price history (for all/most countries) for 0.28 Inch 2.5V-30V Mini Digital Volt Meter is here. The lowest price was: $2.99.
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)).