What Bartsie says about used is spot on. I've had too many customers with bikes they bought for $500 on craigslist that needed $400 in repairs and replacement parts. Projects are fine for experienced home mechanics who know the true value of a five year old bike with a shifter that might be useless, have boxes of old parts, lines on new parts, the time and experience to put in sweat equity, and a reliable bike they can use in the mean time.
Major manufacturers with excellent road bikes in your price range, in no particular order: Trek, Specialized, Cannondale, Scott, Felt, Giant. Have I left anyone out? I'm not to crazy about Fuji's lowest tier, but the Roubaix line at the next price level is nice and often deeply discounted.