The other half are 3 or 4 bedroom, my largest has 9 beds and 4 baths in 3 stories. 

The other is Case Shiller index top 20 largest metros (home appreciation) for past 30 years of historical actuals.Notice anything?

Or see where your target city ranks.TerryTop 100 Largest U.S.

It is one of the largest and highest priced homes in Northfield, so the buying pool is pretty limited. 

I work for Redi Carpet (largest multi-family flooring company in US) and I can get materials and labor almost at cost. 

Loopnet for example is owned by CoStar, the largest commercial MLS in the US and most widely used by brokers; no matter the market CoStar generally will have the most complete set of listings.

As a first approximation I'd probably take records from the largest time frame available, do a linear fit to that and assume the same percentages can apply over the next 20 years.

Accordingly, if you anticipate a large state balance due for tax year 2017 you may want to consider paying that by year end if you are not in alternative minimum tax to preserve your deduction.

If so, you can bill back water/sewer consumption (increasing the NOI and cutting one of your largest expenses)  but you'll want to see if that's common practice with your competition and ensure rents line up as well.

My buddy who used to own one of the largest hard money loan companies in he US, he has since sold it, rehabbed a church to turn into a home for himself.