I have just checked coupons. The lowest price I could get is $18.99 for 300mm 12 Inch Woodworking Scriber Compass Angle Scoring Ruler (in Banggood). Price history, coupons and price alert are available on this page. What is the best price?
300mm 12 Inch Woodworking Scriber Compass Angle Scoring Ruler Adjustable T-type Ruler 360 Degree Angle Marking Gauge
Latest price update (UTC time):
Banggood ($18.99)
Banggood warehouse is located in China. Too bad there’s no coupon right now in Banggood. The question is – is it a good price? Well, this price is higher than average price ($15.74)
Link: Banggood product page
Price: $18.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGd095f9, BGWT15, BGWDT15
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
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
Check out price history chart (for all/most countries) for 300mm 12 Inch Woodworking Scriber Compass Angle Scoring Ruler.
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)).