It would serve you well to discuss these definitions with appraisers and perhaps your local building authority before making a decision. 

It's up to you if you're client will take these consolidated articles at face value or if they need an in-depth analysis then you'll have to go with subscriptions.Another recommendation I got is to follow authors from the main news publication sites that publish real estate market trends.

You'll typically need to set up your account and get familiar with the process of working with the local housing authority.

Is your LLC authorized to incur debt without Investor approval? 

Given that I believe Russell is (IMHO) the recognized authority in the DC area, I tend to believe his data over RedFin.

@Michael Daniel Ultimately, it's all about confirming what the housing authority pays.

We will soon see what the financial authorities have to say.

@Joshua Tucker Building real estate on tribal land offers unique tax benefits, but it requires careful planning and collaboration with tribal authorities.

You just need confirmation from your broker the amount you would receive from the commission (if they take a cut), if you're your own broker you can authorize that yourself. 

Go to the authors' Linked In profiles and see what real experience they have.