I built up a commuter for under $400 - got an old 3 speed in rough shape with a good frame, stripped it and repainted (spray painted in my back yard), got new 650B wheels made up (w/velocity blunt rims), sturmey archer drum brake in front, 3 speed with drum brake in the rear (cheap from niagra cycle), nice Nitto Albatross handlebars, going for the vintage city bike vibe, rides great. biggest thing i learned was to get a 22 tooth cog for the rear to gear it down. I realize that the drum brakes have their detractors but they work great for me, never squeal, dont stop as quick as high end disc brakes but do fine for me. And the 3-spd hub is on the heavy side, but part of my reason for commuting is exercise, so I figure I am just getting a little more exercise with a heavier bike.

You will find craigs list addictive, a couple of months later a Bridgestone Xo-3 came up that I just couldnt resist for the price, its a nice hybrid, has 21 speeds. If I had to do it over again I would probably pick the hybrid with 21 speeds, but I have a real attachment to my "hot rod" I built up myself.