I actually still use the first road bike I purchased, which was about 5 years ago or round about that time. It's a specialized allez (aluminum frame) and I purchased it at a LBS for around $600 if I remember correctly.
Granted it had low end components, but I only had to replace the saddle off the start and was content until I had the money for improvement. I upraded in sections when I could. Some components here, wheels there, a few more components, handlebars, etc, and several seats later...here I am with the same frame and still have no immediate plans for replacement.
I'm sure it can still be done today and with higher level equipment at that. Just gotta keep those eyes peeled. Another option, would be to put together your own bike over time when good deals on pieces come up. Might save you some additional dough.