EJ -- Have you investigated used bikes? I would look in pawn shops, bike shops, want ads, and even ebay. Ask friends and relatives because many people have brand new bikes gathering dust in the garage. Post signs at work or school, and in local store bulletin boards. Put a "wanted" ad in your local newspaper and shopping guide.
To find totally free items, including bikes, google "freecycle" + the name of your city. This will yield a local user list (Yahoo group, usually) where people give away things they no longer need.
It sounds like you know enough about bikes to recognize a good deal. It's amazing how many people want to get rid of great bikes, cheap or even free.