Matt Cutts on Directories
Nice thing about Sherlock Directory is we pretty much follow the guidelines to a "T".

Submitting your website to internet directories
If you recall, Yahoo started out as a directory in the 90's and has since grown to become a tremendous portal. Internet marketers and SEO folks often use directory submissions as part of their plan to promote a site.

Is this site really worth $2226
Ran a neat little tool that gives a lot of information about a site and assigns a value.

Different Prices and Fields for Different Categories
With the introduction of phpLD Classified it is easy to make different prices for different categories, and even completely different link types for different categories.