Most Kershaw knives are pretty cheap. The company that owns Kershaw also owns Zero Tolerance, which is a higher end brand. They use steels like S35VN and 20CV,

Most Kershaw knives are pretty cheap. The company that owns Kershaw also owns Zero Tolerance, which is a higher end brand. They use steels like S35VN and 20CV, which are fairly high end steels. 20CV is roughly equivalent to M390. Not many steels sharpen really easily and stay sharp long. Usually you lose edge retention for ease of sharpening. M390 and 20CV are hard to sharpen but hold an edge really well. My personal favorite is M4, it has superb edge retention, is tough to sharpen, but isn't as stainless so is often coated to prevent rust. Definitely my favorite though. It's just a joy to use.