I have checked all old coupons and price is $10.99 for ANENG VC1019 Test Pen Voltage Detector (in Banggood). Just check coupons out (with price alert and history). What is the best price?
ANENG VC1019 Red Laser Test Pen Voice Broadcast Voltage Detector 12-1000V Volt Current Non-Contact Pen Electric Teste Meter Tool
Latest price update (UTC time):
Banggood ($10.99)
Banggood warehouse is located in China. As you can see I didn’t find any active coupon for this product right now… What about the price? Maybe there’re no more promotions for this item, because current price is higher than average (which is equal $8.49)
Link: Banggood product page
Price: $10.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGTOOS729
(probably won’t work, but you can try them out)
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
Here is price history (for all/most countries) for ANENG VC1019 Test Pen Voltage Detector.
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)).