I ran the numbers 2 ways: at 10 Cap and GRM 78.  

In addition to the cap gains, I think the gross profits affect your gross income on your taxes - in turn impacting AMT and other taxes.   

However the stuff he sends me is generally 7-10% cap and on the 'retail price' end.

And it probably will be less than 10% cap.   

Cap rate is 11%.

This type of scenario works well if the cap is lower or big rent increase of 6 to 10% are occurring in the first two years.

Thought would be use combo of 20K and private/family loan $$ to get into a larger property, cash flowing at some economies/cap rates as my current props and accelerating cash flow.

The formula is : property value = NOI/cap rate Because The building is completely vacant and needs a rehab I don't know what the expenses are or will be except the taxes and I can estimate insurance but I just use the 50% rule to come away with my NOI .

Thanks for the responses @Steven Picker I ran the calculations on a spreadsheet and accounted for PITI plus Maint, Vac & Cap Ex each in the amount of 1 months mortgage; plus Maint in the amount of 1 months rent payment. 

This is with 3.5% down only. cap rate of 6-7%.