If I were doing your numbers I'd subtract 7% from the sales price as well as another $5k for the purchase.

Need to subtract taxes, maintenance, need to add leverage.In my first i consider the all cash investment.What u need to consider:PopulationAmount of units rented in marketTurnoverType of tenant ( fixed job, “student class”, etc)Maintenance ( learning here in BP students are maintenance intensive)Utilities costInsuranceTaxesAlso would get a trusted contractor to gimme another estimate.In the end i would be more prepare to see if i would invest.

Once I subtract the monthly debt payments, I could be barely cash flowing, if at all.

Take the gross income, x .43 then subtract reported monthly bills such as car, credit cards student loans child support etc. whatever is left is what the seller, or borrower, can qualify for. in other words...have them complete a 1003 with a lender to see. 

I would ask an eviction attorney how long evictions take in the area, figure out how much that is going to cost you, subtract out the security deposit and decide on the net if it would be worth it.

I use the same formula for each project although I realize it is difficult to make 20% on a project that needs very little rehab.By the way I subtract a total 12% from the ARV to determine my net proceeds. 

The most I would be willing to pay is total repairs subtracted from the 70K. 

She told me I can subtract the 40K and that would be fair.

If you subtract the rehab you get a maximum purchase price of $56,411.On the second property I see NOI of $4,100. 

Take your discounted gross rent and subtract your ongoing costs to determine your projected net income before taxes and depreciation.