How do you find ARV MultiFam when no 90 day comps to be found?

[Kathy Cooper]

I am in the process of doing the calc for a multifamily - old neighborhood - good income, but needs a good reno. Owner wants to know the Wholesale value but I have no recent comps.

There are many recent SF homes sold, but this home was turned into a good money maker years ago ($3,350 under value rent). 

Any advice out there on using these two bits of info to create a Wholesale value to present to investors? It's a good one.