If you're a newbie, you really should buy the bike from an LBS. It takes skill to make a bike run well. You can and probably should learn those skills but the shop will make sure that the bike fits and that it runs right and it will take care of the bike over time. In the meantime, you can pick up the skills you need. Buying a high dollar racing bike used from ebay has the potential for real headaches; just sayin.