You can't kill Craigslist with that UI.

What makes Craigslist "just work" is the simple, bloat-free interface. It makes it easy to view large quantities of data on a single page, and doesn't make it a "chore" to browse through the site for stuff.

Your UI is really way too bloated. Cut down on all the "web 2.0" look, focus on what your customers need rather than making sure your design screams "I'm a Web 2.0 Startup!"

Cut down on the graphics, the crazy whitespace.

Just my two cents.