The broker is in business to make money like any other business, and I think Dwights no commission stance is not risk free for the broker, and that's the rub.If I summarize what I think Dwight is saying:Mr Broker, I will not bring you one cent in commissions, however, I will provide risk to your business as I will be acting as the procuring cause in transactions that only I will profit from.The whole broker/agent relationship is based upon turning transactions for a commission.

After many properties and many tenants later, I have learned some very valuable and important lessons which I will summarize below.

I truly value it.To comment on a few things you said: Of all the comps I have, I did not only look at the average, I just posted the average to summarize.

Good points all, thanks for your input.To summarize, Elementary School = OK, Highschool = No and Middle School = either way.

These are negotiable on election days only with your state and local government officials.1300's are other fees paid to other people like termite inspections, surveys, buyers premium fees paid to auction sites, etc.To Summarize....Negotiate the 700's with your sales agent before you even start shopping for a house. 

Instead, my eyes were glazed over while someone summarized over my shoulder "Oh, that's just required by the state

@Francis Rusnak refer to the Chicago zoning chapter 17, the link here should summarize the amount of allowable units based on zoning: https://export.amlegal.com/media/12b70ab4bc42a5c7791edc1ccb4024289a556667/DATAOBJECTS/0-0-0-38364.pdf

@Joe SplitrockOnly thing I do differently in my process is during the discussion I let them know that unfortunately since it was in the lease and they “forgot” or similar I will be following up with a written warning summarizing our discussion within a week.

So to summarize - it looks like the due diligence is mostly the same, however there needs to be even more caution taken when checking and verifying the payment history, so make sure to do things like obtaining bank statements and even an estoppel like agreement.

So to summarize, my question is not on how to get a super accurate estimate of ARV/Repair costs, but rather, how to get a good ballpark estimate when I'm only looking at a few pictures and a short description of the property on sites like MLS and Zillow, or when Driving For Dollars.