Go down and check coupons out. Remember to check price history if it is available. 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 coupon and price update (UTC):
Measurement Mode Quick investigation / automatic detection, Test Range 0.00-0.19%BAC (0-1.9g/l), Unit Of Measurement mg/l (BrAC) mg/ml (BAC), Shell Material ABS plastic, Blowing Time Within 10 seconds / the requirement is greater than 4 seconds, Model AM01, Power Supply Built-in rechargeable polymer lithium battery, Packing Weight 46g/color box (host / charging cable / manual), Measuring Time 20 seconds, Display LCD liquid crystal display (black and white), Power Adapter Requirements DC5V 1A, Working Current 250MA (max), Warm-Up Time 10 seconds, Sensor Type Semiconductor sensor, Packing Size 100*78*22mm, Standby Current Less than 20UA, Response Time Less than 5 seconds, Use Battery 3.7V 140mAh can test 150 times continuously, Working Temperature 0-45℃
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($14.95): BGSCM11
2. ($15.97): BG589b2e
this code has to be applied 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
Old coupons (from the oldest to the newest): BGf1b5e5, BG00c906, ADMITAD2212, 2022ACTIESNL, BG01ccf1, BGa607ae, Terence, Tabby20, BG03485d, BG1efeb0, BGecface, MVC8SPRING, 8BGwbg2204, BGAUTO22, BGdd5c68, BGdcbfa8, BGfd33ae, Cuponation9, BGSCM75
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Check out price history chart (for all/most countries) for AM01 Alcohol Tester.
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)).