Calculating Market Value

[Kim Ford]

Need some guidance folks.  I have comps from a real estate agent on a triplex.  I know how to do the calculation but the comps are based on single family residences and the property I'm researching is a triplex in a residential neighborhood.  So, essentially, the comps are not based on other sold triplexes in the area.  The real estate agent did research to find other triplexes that have sold and could not find any so he worked with what sold in the neighborhood recently, which wasn't much because that part of town has its issues.  How should I move forward with this?