$9.99 – Digital Alcohol Tester LCD Display High-precision Breathalyzer Professional Alcohol Breath Rechargeable Alcotester Drunk Driving Test – #1.
According to my DB the lowest price is $9.99 for Digital Alcohol Tester LCD Display Breathalyzer (in Banggood). You can create price alert here, copy coupons and view price history. Best price?
Latest coupon and price update (UTC):
Banggood ($9.99)
Banggood warehouse is located in China. Low/high price? Let’s see… Average price for this item is $11.25 and current one is $9.99, so it’s a good price! There is one coupon available! Pretty cool, huh?
Link: Banggood product page
Price without coupon: $10.99
1. ($9.99): BG5c7ab6
apply it in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BG28a357, BGAMMT03
(you can check these old coupons out, but these probably won’t work)
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.
Price history and price alert
Check out price history chart (for all/most countries) for Digital Alcohol Tester LCD Display Breathalyzer. The lowest price was: $9.5.
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)).