Karambit Knife (Banggood, Aliexpress: Handle Material: ABS/Stainless Steel, Blade Material: Stainless Steel (the best price with coupon)).
Basically copy coupon, view price history or create e-mail price alert. You probably want to know what is the best price?
Aliexpress
I could not find it on Aliexpress. Click here to search by yourself.
Here are coupons that you can use.
Latest price update (UTC time):
Price history and price alert
Check out price history chart (for all/most countries) for Karambit Knife. The lowest price was: $3.58.
Price records source(s): Gearbest
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)).