If you go to a lbs you may pay a bit more but it is worth it if you don't know how to fit yourself or don't know much about bike upkeep.

If you know your stuff then the on-line bike sellers offer deals that are hard to match...supergo is one for example. If you don't mind not getting a full group of campy or shim than there are some real good deals for price point bikes with mixed groups in the 1500 to 2000 buck range.

Used bike are a lot of work and you need some luck.

I agree with the alanbikehouston's view as well. That is what I would do.