some thoughts...
Spyderco delica - the saber ground and ffg ones in vg10 steel can be had for around $50. Or you can go up to the zdp-189 blade for about $85.
Kershaw leek - standard version with sandvik steel can currently be had for under $30. The composite version has a cpm-d2 cutting edge and is around $50. There is also the s30v version w/ g10 scales (and liner lock instead of frame lock) that can be picked up for around $70.
Benchmade mini-griptilian - standard version can be had for about $70. Ritter version (wider, stouter blade and s30v steel) is about $120. Or, you can build a custom griptilian on benchmade's web site for $115. You can pick your own handle colors (different color for each side if you want), blade shape, blade steel, lock/liner colors, clip, and even engraving & image printing on the blade.
Spyderco sage series - prices vary by model. Each model features contributions to the knife world by various designers. Check out the spyderco page for details on the various models. The sage 1 (carbon fiber scales, liner lock) and 3 (g10 scales, piston lock) are the only ones that fit in your stated price range though. Those run around $100.
Buck vantage pro (small) - very solid-feeling little knife. S30v steel, bos heat treat, contoured g10 scales, deep-carry clip. Runs around $50.