I would also say that unless you live in a fairly flat area with lots of people, you won't get that much range on a CB. Most CBs are only 5w so with mountains, tall buildings, etc, you might get a range of 1 mile. I recently tested my mobile/base CB at my house, and while I was picking up a lot of chatter (agreed, most of it is crazy talk) from all distances (some were hundreds of miles away), my broadcast range reached about .5 - .75 miles. We tested this with a handheld ham radio to my CB.
Overall, they're fun to turn on and listen every once in a while, but you can essentially do the same thing with a scanner. On a positive note, if you really want to buy a radio to experiment with, CBs are fairly inexpensive. I'd recommend an old Radio Shack handheld or Cobra LTD Classic for a mobile/base unit.
You'll have a lot more fun with the ham radio.