Does anyone have a method for finding the data needed to calculate how much equity a potential seller has in their home??

@Patrick Fermo - Citi Data and Neighborhood Scout are decent resources for market analysis. 

I'm probably going to make a post in a more appropriate forum asking for comps of comps software (pun intended), so I can find a good centralized data source that I can just crunch numbers on.

My sql database also contains all of the MLS sold,expired,withdrawn data for the past 3 years( proprietary to the MLS board) If the property fits 80 to 85 % of where my number need to be, only then i visit  the property, then refine my spreadsheet info and rerun against my sql database.

So I read somewhere here that Phoenix AZ might be a nice place to start investing and I'm using realtor.com to look around since I know nothing on any area here in the US..too big for me (Israel..you can understand why :) )I found the following duplex:https://www.realtor.com/realestateandhomes-detail/...According to some basic analysis I've done, hopefully I did it right, I don't think it is a good dealThe data I pulled off this listing:Price - $175K$750 * 2 rent$1028 tax (I think this is too much according to https://mcassessor.maricopa.gov/mcs.php?

In my area a duplex rents for more $ total than a typical SFR.I wish I would have kept data through they years on turnover. 

Could be a data entry error that caused the discrepancy.

All purchasers of rental property should independently contact the municipality where the rental property is rented to verify (at a minimum):  1) rental license valid and what tier (if exists), 2) any open work orders on the property and when was the last inspection, and 3) any criminal activity at the property (public data request). 

One nice little thing (included in the 'free ninety nine' package) is that you can set it to spy on your outgoing emails and automatically add people, to save time on data entry (#1 reason people who should use a CRM don't is the time suck on data entry).

What you are investing in is the real property...if you torture your data long enough it will tell you anything you want to hear.What video are you referring to?...