A20 Alcohol Tester is for $9.99 (in Banggood). You can create price alert here, copy coupons and view price history. Let’s see what best price is ATM.
Latest coupon and price update (UTC):
Test Range 0.000-0.199%BAC, Model A20, Material ABS, Size L*W*H 100*28*17mm, Working Environment 0-45℃, Charging Input DC 5V, Product Name Portable Alcohol Tester, Power Interface Type-c Charging interface, Battery Capacity 200mAh, Sensor High precision sensor
Banggood ($9.99)
Banggood warehouse is located in China. CouponsFromChina software could not find any coupon for this product in Banggood. The question is – is it a good price? Well, this price is higher than average price ($9.99)
Link: Banggood product page
Price: $9.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BG990444, BGSCM11, BGXIFD218, BGCRT313, BGd7a0f7, BG0fac59, BGCAR639, BGf2f7ba, BGae6cae, BG6de04b, BGRFEBPA20, BGAMMT03
(these coupons are old, so probably won’t work)
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
Do you need price history chart (for all/most countries) for A20 Alcohol Tester? There we go.
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)).