Check out who is bidding on the properties, there are regular guys at all of these things.

Check with any lender that you might work with to see if they are okay with 'vacant refinances', that will usually let you know if they need a tenant in there or if they are okay with vacant properties (and usually okay with Airbnb-type investments as well).Good luck!

Did you do a background check?

The older ones, just need more due diligence, but still make perfect sense.As some people were complaining about old houses, it sounds like they didn't do proper due diligence because if you don't check the plumbing with a scope, then its your own fault for not verifying the plumbing with a scope.

Check out some of the great things happening in Detroit in 2024https://michiganchronicle.com/2024/01/03/major-developments-that-will-define-detroit-in-2024/

Another method is you can search for comps in the area to find a duplex that is similar to your subject property - check the rent of duplexes nearby and make estimates.

You never know when your next commission check is coming.

Last two years of tax returns, credit check, pay stub, etc.

As I said... open a few tanks and check for backflow, visit the health department and ask a few residents if you can. 

After trying to read that I had to check a mirror to see if perhaps I had a stroke.