Current Karambit offers across twelve marketplaces side by side, with the lowest price in each exterior and how it has moved over time. Set a price alert to be told when it drops.
Karambit is listed on many marketplaces at once, and the same item can cost noticeably more on one than another. This page puts the current lowest offer from each side by side, with the price history and recent sales, so you can see where it is cheapest right now.
Set a price alert and you get an email when Karambit drops below the price you name.