The majority of my clients come to me after doing their own books for a couple of years and not a single one of them did their books right 😬 You can get away with mistakes with less income and maybe one or two properties, but you'll want accurate financial reports and data if you plan on acquiring a number of investments and funding.

(I have been remodeling for over 15 years and I am an engineer, have done probably 300+ home inspections over the years, so I know a thing or two) But there are exceptions: if we are on private well and private septic, lab test and septic test should IMO be done, because I can't tell visually whats going on.

Interior upgrades you can test and pay as you go. 

Over 70 years of data.  

For emergencies (fire, water, structure) they should call Latchel who then, in theory (again, never had to test it yet...thankfully!)

STR/MTR out of state is a solid angle, particularly if you’re pairing it with strong data and boots-on-the-ground partners.

I have had test callers call in the past to make sure I am following fair housing and civil rights acts on listings. 

Many landlords double-check with tools like TransUnion SmartMove or RentPrep to get cleaner identity matching and more reliable credit and background data.

Fire ratings, STC ratings, sprinkler systems, air barrier testing, and costlier mechanical systems—much of it driven by regulatory changes—are all at all-time highs.

I've done it and many in my network do it successfully.For market research, we use Zillow and PropStream for comps, property data, and neighborhood analysis.