With comps ranging from $875K-$1M and your estimated build cost at $550K, the after-completion value gives you a significant equity cushion, making this project highly attractive to lenders.If you plan to hold and rent the property, you could refinance into a DSCR loan after construction, which bases lending on rental income rather than personal income.

I've walked their properties in-person, and their build quality is good.

Ask your employer if you can have your pay split up into three deposits, one to investments savings, one to your checking account for personal use on a daily basis, and one to an emergency account you can tap into so you don't have to tap into your investment savings.

Yes I have known it to work because the owner is not a push over, enforces policy and can make it run good......however, do you have the right personality to do this, AND if you move out can you continue to have the house run smoothly with no one in charge.  

And what if the one person you didn't check has a criminal background, has collections, and more?

Not talking about you personally.

Dumb question - but are these auctions online only, or in-person? 

Exploring other options like Appfolio or Apartments.com which might offer the balance of support and functionality you need, is a sensible approach.

I personally will try to avoid buying a home under 1000 square feet again.

I lived there from 2017 to 2022 and personally witnessed significant changes during that time.