Net Operating Income is Income - Expenses Before the mortgage. 

There services in some areas (not mine) that specialize in probate lists.

It's $350, but if your policy is more than $4k (or higher like mine), you'll come out ahead.

After Operating Expenses are deducted, we're looking at about $13K in NOI.Purchased for cash at the full asking price of $244,900, and assuming NO CapEx or renovations, that's about a 5.3% Cash-on-Cash return.What am I missing?

I feel like I found a gold mine. lol.

And while there are a ton of people on these forums and social media that I would never trust my money with, there are also a lot of people/companies that are on social media that are great operators with long track records.If you are not going to go that route, I recommend you start hitting up local meetups and REIA groups.  

The seller is a client of mine that was looking to sell it.

A friend of mine is co-owner in a drug rehab clinic that operates in Southern California.  

We include real expenses accustomed to STRs so you can see the actual operating costs.

What are the operating expenses of running the Airbnb?