Appraisers: What if there are no comps?

[Michaela G.]

I'm buying a duplex and the first appraiser just backed out, because he couldn't find any comps. 

What happens when there really aren't any like properties that have sold within the past 6 months? 

Nobody here sells their duplexes, because they're cash cows. So, the only other duplexes that I can find are either a 1/1 900sqf fixer-upper for 20K or a 2/2 1400sqf fixer upper for 75K. This is a renovated 6/2 at 1800sqf. 

Do you keep going further out, miles away? Do you use the fixer-uppers (which really isnt fair) or is there a time when you're allowed to use the income approach for a duplex?