The problem with many auction type of sites is they don't differentiate the site types. So blogs are mixed with commerce or personal sites, making hard to find what you're looking for. There is also lots of hype because of shady methods to pump the site rank or traffic figures, in order to sell.
Going after a web business requires you have some fundamental understanding about the business itself and how the revenue is generated. If you are a descent merchant find an ecommerce site that is on sale and see if the merchandise is something you can handle.
Personally I would prefer to go after commerce, than risking investing to a site only because of traffic.