There is a back of the napkin formula in flipping that is essentially (purchase + repairs) < 70% of ARV.

My lease specifies that she has to maintain a sanitary and habitable condition for the property, however you define that. 

Some cocktail napkin calculations will give you a good sense of the cost advantage either way.Another option would be to do a complete exchange and purchase two properties rather than just the one. 

I would literally buy deals that made sense on a paper napkin that I could quickly write up numbers and see if it would work.

(Due to pending legislation)For houses that have been vacant for an extended time, camera the sanitary and storm sewer lines. 

Is he a write it on the back of a napkin guy?

In other words, using your numbers, if you are sure the house will appraise for 800 and the reno cost will be <= 180k, they you will end up ahead; if they will cost more than 180k, you will be behind.You can also rent it out for X years at the higher cashflow, then reno it during a future turnover when you are more stabilized.Lastly, being this is your first investment, I would recommend waiting on the reno until you see how the place rents out and other learning experiences.You did not share your numbers, and I don't know the exact taxes in Rye brook, but making some assumptions, my napkin math suggests that you will need to pull in around $4,800 per month to make the $1000 cashflow. $4800 seems high.Feel free to PM me if you want to chat more.Best of luck!

This deal is so complicated and napkin calculation doesn't show me much cash-flow.

Give them your income and current debts , and rough credit score - and they can do a quick back-of-the-napkin loan calculation.

The reality is that I keep looking in this area (Fort Wayne specifically) and with quick back of the napkin math, literally everything fails to cashflow using the same #'s and %'s I provided in the OP.