I got a couple of mics from radio shack when a friend was in a band and wanted to do some recording. The cheap one was sucky, the two more expensive ones were pretty good. This was in high school, so even with several people chipping in our budget was small. The total for all three was maybe $100. They had a condenser mic that was actually quite nice-- condensers are the type that you put a battery in.
Cool Edit, after being bought by Adobe, is now Audition. Quite expensive. I recommend
Audacity for recording. It's free, has a good feature set of the standard filters & effects, and is specialized for multitrack recording. That might be something you need for voice overs. If not, you don't actually have to use the multitrack stuff. best of all it is free.