Hard to say if it’s a good deal without the most important piece of data, what is the fair market value? 

Important things to look for: if you want to STR (you will make more this way) then no rental restrictions, if you plan to MTR, 30 day min works, anything longer doesn't.

This is important for first time landlords. 

As RE developers we all know how important it is to hire good, reliable residential contractors. 

Even more important if its old lath/plaster. 

While I’m not an expert on the legal aspects of posting here, I do have years of experience coaching students in real estate sales and investing.For anyone getting started in real estate, I always emphasize the importance of focusing on key steps before committing to a deal.

I’ve been looking at on-market deals as a starting point, but I know the importance of sourcing off-market opportunities.

If you are considering buying using Subject To - Subto, it's important to know what your exit strategy is.Talk to a mortgage broker (not a bank) and ask if that is a property you will be able to get financing on in the event you have to refinance quickly, because the Due On Sale clause was called.AndTalk to a real estate agent about how much you would have to bring to closing in the event you had to sell quickly.

How keep it legal of course but more importantly how to do if effectively.

For most, this isn't a realistic option so they update some of the most important regions themselves and copy the data from other providers where they don't have coverage.This is a big problem with these big consumer-grade real estate analytics platforms—you don't really know the source of that data, its frequency, etc.