Latest update shows that UNI-T UT373 Digital Tachometer costs $23.99 (in Banggood). You can create price alert here, copy coupons and view price history. Let’s see what best price is ATM.
Drop test 1m, Display 5-digit segment code; 99999 max display, Refresh rate About 1s to 7s (depending on the speed, >120 rpm for 1s), Storage temperature and humidity -20 ° C to + 60 ° C (no more than 80%RH), Battery life Continuous work for 12 hours, Product color Red and grey, Protection rating IP65, Working temperature and humidity 0 ° C to 50 ° C (no more than 80%RH), Power supply 3 1.5V batteries (AAA) (NOT Included), Target distance 50mm ~ 200mm, Measuring angle The angle between the laser and the surface being measured is less than 30 °, Product size 183.8x 56x 34mm, Product weight 85g (excluding battery), Sensor type Photodiodes and laser tubes
Latest price update (UTC time):
Banggood ($23.99)
Banggood warehouse is located in China. There are no active coupons for this product, but the price is pretty low isn’t it? Is it a reasonable price for this item? Well, this price is higher than average price ($14.99)
Link: Banggood product page
Price: $23.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): 502C6B, 15ANENG, AFfbG10, BGVDay10%off, BGAFF10OFF, BGTT10, bGhOnEy10, 13f142, BGherra, BG195eb3, BGGines, Tabby20, BGTools8, BGM1TOOLS88
(there’s a little possibility that old coupon will 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
Here is price history (for all/most countries) for UNI-T UT373 Digital Tachometer.
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)).