Jason X wrote:
at that price range, get the one with the best component group. You'll be better off with an alumnium frame and ultegra, if you can find it. Manufacturer really doesn't matter. Just get the one that fits and you like the most with the best components.
If you want to roll the dice, look at Felt. They have hit or miss quality control, but they're decent frames with a great component spec for not a ton of money.
Yup that's great advice.
If you plan to eventually use it in a triathalon or something, go with drop bars, and then you can easily attach some clip on aerobars if you want them later.
Also, if you have a choice, go with better wheels. A lot of low end new bikes these days use really poor wheels that break spokes and stuff pretty easily. Personally I would go with a little lower quality frame to have enough $ for a little better wheel.
If you know what you're looking for, you might be able to find some nice deals on craigslist. But if you get a used rig with anything carbon on the frameset, check it over very carefully for cracks and chips.