Help with calculating appropriate offer price on multi unit

[Chris Lupcho]

I have an opportunity to purchase an 8 unit property but struggle with calculating an offer.  My issue is with figuring in approx 150K of deferred maintenance.  

Numbers look like this:  Gross income 72K.

Taxes and insurance 12K

Property management, vacancy and maintenance - approx 20% (14K).

NOI 46K. I believe that a 10% cap for my area is appropriate - therefore I would put a value of 460K on this house.

My issue is that it probably needs 150K because of neglect - past due issues of roof, windows, siding, etc.

Should I take the value and subtract the repair costs - resulting in a value of 310K?

Thanks for any help,

Chris