Scanners

[Commonman]

I was at the photo shop yesterday and asked about a scanner that would do a good job at scanning negatives. They suggested the Nikon Coolscan but it was about $500. Is this about the lowest cost scanner that will do negatives? Also, how is the resolution of the scanner measured? I have seen one number (dpi) and a two number parameter? Which is the best to use? I'm confused.