[masraum]

I haven't ordered from them, but this place has always looked like it had good prices to me.

http://www.knifecenter.com/

I like Benchmade knives. There should be several under $100. There is the inexpensive line that has plasticy handles and then there is a better line that usually has Al or G10 handles. You should be able to find a few of the better line for <100. That's what I'd go for, especially something with the axis lock. That way the blade has a positive lock, but you can easily open and close the knife with one hand. (axis is also ambidexterous, so it's lefty friendly)