You can get Small Square Center Finder Tool 50x100mm for $6.99 using coupon code (in Banggood). Basically copy coupon, view price history or create e-mail price alert. Best price?
Small Square Center Finder Tool Compact 50x100mm Aluminum Alloy Mini Square Ruler Precise 90° Marking Center Finder – Metric
Latest coupon code price check (UTC time):
Banggood ($6.99)
Banggood warehouse is located in China. There are no coupons available at this moment in Banggood. Price? It looks like it’s a good price (lower than average ($7.49)).
Link: Banggood product page
Price: $6.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
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 Small Square Center Finder Tool 50x100mm.
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)).