I would suggest you might also consider some of the traditional style pocket knives like Swiss Army Knives or Case folding knives. These are the ones that many people may have grown up owning as a kid, or remembering their parents or grandparents using.
Victorinox Cadet, Rambler, Pioneer, or Electrician are some that come to mind.
Case Peanut, Mini-trapper, or mini-Copperhead are some others to consider.
Buck also makes some decent traditional styled knives.
The good news is that for $100 you can probably get two or more of any of those listed above.
There are some higher-end traditional folders that come in closer to or in some cases well above your $100 mark from Great Eastern Cutlery (they have several sub-brands), AG Russell, Queen Cutlery to name a few others. AG Russell also has some lower priced models so I shouldn't lump him in with the "high dollar" folders only.
If you're looking for something in the more modern styles then you've got a lot of good advice so far. I'd consider one of the smaller Spydercos like the Dragonfly, Manbug, or Ladybug, they are unlikely to arouse much fear due to their size and blade shapes, and can be had in handle-colors other than black.