Looking to sell a duplex but having trouble determining value

[Penny Wilkinson]

How are appraisers approaching value on multi-family when there are extremely limited comps available?

I am considering selling a two-unit in West Texas, but only one duplex has been sold in town in the past eight years. I've talked to two local agents about possible price points to list at, but it almost seems like they are pulling numbers out of a hat. I'm curious what others have run into when comps are very limited.  Rents are high in this town and I think folks just don't sell their multi-family units very often. 

[Nathan Gesner]

Quote from @Penny Wilkinson:

I'm in a community of 10,000 and deal with this quite often. I priced an off-grid home when there were none sold in over six years. I am currently selling a 16-unit apartment complex, the first one to sell since 1998 when this buyer bought this one!

• Sales comparison A common method that compares the property to similar properties nearby and their relative prices. This method is simple but not precise.
• Cost approach A straightforward method that adds the cost of the land to the cost of building construction.
• Income approach Also known as the rental income approach, this method estimates the market value by analyzing the property's anticipated future income and converting it to a present value estimate.
• Gross rent multiplier (GRM) A method that divides the purchase price by the gross annual rents when the property is 100% occupied. This method provides an indication of value based on the property's rents.

I try to evaluate a unique property 2-3 different ways, then make a highly educated guess based on my knowledge of the market.