No Comps - How do I get an ARV?

[Adrienne Donner]

I found a great triplex with lots of potential but my realtor can find no sales comps within the last year in the area. It is in a section of the city that is separated from the rest. 

How will an appraiser evaluate the value in such a case? How can I analyze the ARV to know if I should move forward on this.

I called my insurance agent to get a quote and he suggest the rebuild value at $67K more than asking. But I'm estimating about $60 in reno. Even on the low end of rental rates it seems promising.

First deal rookie here. Your advice is much appreciated!!