If I did my math right, which maybe I did not this seems to be preferrable...Borrow 55k out of my home for about 350 a month extraNew loan about 1400Rental income about 1900Which should leave me about $500 cash flow.200 for rental agency and 300 a month into a fund for repairs until that gets reasonably high and I can start taking profit.Am I missing something?

I am a high school math and computer science teacher and got my real estate license a while back and just recently got it reinstated.  

. - $200Utilities - $400Total Monthly Spend: $8400Now I didn't plan the math this way but it worked out to be exactly about what a 200k earner would bring home, post tax, each month - which effectively means this theoretical person is living paycheck to paycheck. 

If so, it becomes about math at that point.

A higher appreciation area will always have better actual cash flow given enough time than the lower appreciating area (simple math). 

Also there isn't going to be a trade secret in your math if you are looking at rental properties that a realtor could steal, same with flips, but flips are more unique every time. 

This would be the only way to ensure your math is right.

There are no consequences outside of that initial outlay of cash if your math ends up being wrong, or if a toilet breaks, AC goes out, basement floods, roof leaks.

To make the math a little easier I doGross rents - %30 (vacancy, maint, and capex) - PITI (principal, interest, taxes, ins) = long term average cash flow.

I work in the NYC area and looking to house hack in Jersey City but when I do the math im not getting any cash flow.