Hey, getting her a road bike is the first step. My wife doesnt even want a road bike.
I guess the first thing is you need to figure out what cheap is to you. The shop I work at, we sell cannondale, trek and giant. If I were you, I'd look into the cheaper giants. They're quality bike and their aluminum frame dont beat you up quite as bad as trek's alum. frames. I know people are going to be pissed but I'm not trying to start a war of brands here. That is just from my experience.

You may be better off looking for a used bike at that price. Here's the problem: there are cheap road bikes out there, but they are specced with component sets (especially derailleurs and shifters) that are poorly functioning, prone to breakdown, and in general no fun to ride. If your bike is no fun to ride, you won't ride it. Ergo, you've spent $500 for nothing.

It is better to find a used bike with better components, assuming all is in good shape.

Trek, Cannondale and Giant are all VG brands that may possibly be available used with the components you want for around $500-600 (OK, maybe finding a good Trek would be tough at that price). Felt & Specialized are also good bets. You'll get solidly built, light frames with all those brands.

Check out the classifieds on the various bike and tri forums. Don't be shy about posting a "WTB" (wanted to buy) message--someone may have a bike gathering dust that your message prompts them to sell. Go to eBay, but I think it is harder to get a good deal there on a complete bike.

I second the idea of buying used. I got my first road bike for $218 on eBay and it turned out great for a beginner. There was nothing wrong with it at all - it was just 15 years old. I sold it for $200 two years later.

I think with a little patience (I really mean just a little) you could find something just right for her by going the used route, and still be well within your $500 budget.

I double the craigslist. I got my commuter and hubby got his race bike there---both really good deals

I got my wife a Windsor from Bikesdirect.com last year. It was around $400. She is not real tall so it was the smaller model with 650cc wheels. Overall, I was really impressed with it for what I paid for.

It had an aluminum frame that looks pretty sound/solid. Nice welds, nice paint etc... It had a women specific saddle along wth extra brake levers on the upper part of the bars. Nice for her as she has small hands.

The only beef I had was it had Shimano Sora, which is low end entry level stuff. But for the price I was pretty happy with it overall. If only now I could get her to ride it.

Its a bit ridiculous to say that just because components are cheap that the bike will be no fun to ride. That is the whole "Its better just because it cost more" mentality. Sure, they're not quite as nice as the more expensive stuff but it doesnt mean they're going to break easily or all the time. Please. If she likes to ride, she'll ride it.

Definately go used. I would almost even recommend going for an older bike with down tube shifters. You can get a bike of that era with older Dura Ace or Ultrega equivalent real cheap.

Go for quality- even if its older. The lower end compnents will work for a while, but that plastic will break and wear down faster. If you can find a decent bike for under $300, do it. Let her learn on something and have room to grow into a nicer bike if she decides she likes riding. I wouldnt wanna blow a wad of money on something she hasnt tried extensively.

Problem with that is the time of year. Last years models are more available from October- Feb. Its mid May now, so most 06 stock should be out the door- except for odd sizes.