If you're looking at Kershaw blems, you might also check out the Leek, OD-1, and Zing. All are in the $25-30 range. The Cryo also typically runs around $30. If you like the Chill, also check out the Volt II or OSO Sweet. Many Victorinox SAKs are also below $30. They're well made and provide a lot of utility. Hard to beat the value you get from a SAK.
The Ontario RAT-1 mentioned before is also a great knife. CRKT has a few that may be worth looking at in this price range too: M16, Drifter, and Ripple. The SOG Flash I is right around that price as well and is practically invisible in pocket (very lightweight, compact, and deep carry clip). The KaBar Dozier Folding Hunter is also a nice, lightweight knife for around $20. The Opinels are a bit different style, but they are great performing knives as well. The Chinese knives (Sanrenmu and Enlan) are also surprisingly well made. The SRM-763 is a pretty neat design, and a lot of people like the SRM-710. The EL-01 is a beast of a folder for under $20.