As far as classified advertising themes or templates go for creating your own website easily, I would recommend this theme to get a classifed advertising website up and running in just a few minutes.
Personally I have used this theme to make a lot of money, mainly from niche websites where the listing fees can be as much as $200 per listing. Just think, what kind of content could you make people pay to post.
What about a niche yacht classifed advertising site, or a local property site where you could charge local agents $50 per listing no problems.
This is a great wordpress shop theme with paypal built in so you can take payments from your users easily. Its always a delight to see cash rolling in from my classified advertising website when I check emails in the morning.