$20.99 – Wnew MM/Inch Precision Woodworking Square Aluminum Alloy Ruler Carpenter Line Drawing Marking Gauge Hole Scribing Ruler – 100mm.
I have just checked coupons. The lowest price I could get is $20.99 for Wnew mm inch Precision Woodworking Square Aluminum Alloy Ruler 100mm (in Banggood). You can create price alert here, copy coupons and view price history. Let’s see what best price is ATM.
Latest price update (UTC time):
Banggood ($20.99)
Banggood warehouse is located in China. There is no active coupon in my database right now (for Banggood). Isn’t it too expensive? Let’s see… Average price for this item is $23.32 and current one is $20.99, so it’s a good price!
Link: Banggood product page
Price: $20.99
Additional Banggood coupons: first page and second page
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
Do you need price history chart (for all/most countries) for Wnew mm inch Precision Woodworking Square Aluminum Alloy Ruler 100mm? There we go. The lowest price was: $19.99.
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)).