Classified Site using Jooma/Wordpress or open source script

Need to develop a classified site for real estate. Along the lines of these sites but focusing only on a certain section of real estate. [login to view URL] [login to view URL] [login to view URL] [login to view URL] Payment Integration with paypal will also be required as users will need to pay to post an ad. Need an open source platform. My thoughts are using Joomla with some plugin. Design will be provided but the site will be designed based on suggested platform so there will be a wait of about 7 days before you get the design and start work. Budget <$100. I see the following as the key activities from the freelancer: - Identifying the tool and plugin to use. - Installing the tool and plugin - Design the theme based on design provided - Configure site based on requirements (most of this will be done by me but may need help) I looked at Noah's classified and really liked it but apparently has a lot of issues and support is bad so didnt go for that. ([login to view URL])