Once you know the typical price and the typical rent you can use a tool I created to determine if you can make money in that market. 

For instance, here in the Dallas area, we have access to North Texas Real Estate Information systems (http://www.ntreis.net/).You could also check out the Real Estate Center at Texas A&M University, which has links to tons of different research tools. 

We ran a property we were looking at by our HML not to long ago. He sent us back a very detailed analysis. It included population statistics, growth, aerial photos of the land, ARV, school district reports, salaries, ...

The assessment value is just a tool for calculating property tax. 

Im so glad I ran across Biggerpockets,  so far it has been a great information tool and I cant wait to get more involved with the site.  

Unless you are an experienced investor and are using the fact that you won't be asking for a buyer's agent commission as a negotiating tool then there's absolutely no advantage that I see to going it alone.

@Jeff Trevarthen We looked at it an a couple of others, but in the end wrote out own (helps that we are originally software geeks) as we needed a tool capable of analyzing deals in Canada.Another product which may work for you is InvestorApt multifamily analysis (www.LincolnSteele.com).  

HUD has a search tool on their website you can use to search for consultants by name or area.

For me, the benefit of the franchise route are the tools, processes and business support it provides, it is still up to me to effectively build my network and customer base.

It's kind of an interesting idea for a tool/feature for BP.