I bought my wife the Coast P7. 200 lumens, bright enough to blind someone temporarily and hard enough she can hit with it. AMazon has it for $65 right now.
I use a Surefire E2D Executive Defender. it's the older one. The newer one is LED and much brighter. However, I like mine and am confident it will get the job done when necessary. It is well over your $100 range mentioned though.