To hit that $100 requirement look at the Uniden BC355N scanner. Can be had new for your price point. Pretty user friendly and scans right out of the box. This was my first model and was very pleased with it for it's cost!I recommend you get a Uniden BC125AT. Check it out..I think you'll like it!
I might get another at that price. The BC125AT is definitely worth the money IMO.Just a quick FYI the Uniden BC125AT can be had for $103.94 as of today. Pretty great price IMO.
When I got mine on 7-10-14 it was $109.88 although I stated $112 earlier.
Amazon.com: Uniden Bearcat 500 Channel Alpha Numeric Hand Held Radio Scanner with CTCSS and DCS (BC125AT): Electronics