analyzing potential property questions

[Susan Clark]

So Im interested in purchasing a property i my town but I'm not sure exactly how to do the numbers, this property is currently a 2 unit multi use building and the rents are $500 and $700 yearly taxes $2050 utilities run 5k there is great potential to make a third apartment on the first floor say a 2 or 3bdrm unit. I estimate it may take 10k for the renovation. The owner is willing to hold mortgage and the interest rate would be 8% how do I figure this correctly. Whenever i analyze this on BP i come o=up with crazy numbers. How should I figure this out.