So it might as well be a future stream of passive income.Debt is a tool! 

Real estate is highly local, and I would say that there isn't one end-all-be-all tool to do market research.

Bigger Pockets Property Insights tool has been useful, even if it's not perfect, it does list known ads, and it indicates the confidence level that it has in its valuation.  

Also, is the Zillow calculator a useful tool?  

I’m personally not buying properties to sell tomorrow, I’m buying properties so that in 30 years I can wake up and have a cash cow fully paid off that just so happened to double in value and double in rents.

I've been using propstream including using the automator tool and done post card campaigns, but mostly use PS for;   I've had PS for 3 years about

Those are more geared towards Realtors but should work just fine for anyone.You can also try PropStre@m, but I think it looks a tad pricey for me, although I have a lot of tools that do the same things for free with my MLS membership.

Full disclosure here though - ARM's are preferred lending tools from lenders.  

This is a positive position to be inMaking money when you building your homeJust imagine in 30 to 40 years new built house possibly double in value    ( markets up and downs )Congrats

Perhaps it makes sense for your personal situation, but I use my cashflow to purchase other properties, tools and equipment (such as a lawnmower) I need to be successful.