According to my DB the lowest price is $7.99 for ENJOYWOOD Precision Chisel Honing Guide Sharpening Jig Tool (in Banggood). Price history, coupons and price alert are available on this page. Let’s see what best price is ATM.
ENJOYWOOD Precision Chisel Honing Guide Sharpening Jig Tool Aluminum Alloy for Chisels and Planes for Razor-Sharp Woodworking Performance
Latest price update (UTC time):
Banggood ($7.99)
Banggood warehouse is located in China. I’m afraid that there’s no working coupon in Banggood. Is it cheap? Cool, average is $9.56, so current price is lower!
Link: Banggood product page
Price: $7.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BG76cfa1
(I don’t think these’re gonna work, but you can try ’em out anyway)
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 ENJOYWOOD Precision Chisel Honing Guide Sharpening Jig Tool.
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)).