Talk with real estate brokers and property managers in the area to find out the absorption rate.

What are absorption for inventory levels doing?

Sellers market = more demand for homes, less supply.A rule of thumb metric I used to use is called "absorption rate", which refers to how long it would take every active listing to sell given the current pace of sales happening.So if there are 100 listings on the market, and an average of 25 sales a month happening, the absorption rate is 4 months.My rule of thumb is less than 6 months tends to tilt towards a sellers market, more than 6 towards buyers market.

Prices might be high, but they are not building enough homes to keep up with absorption.

You want cost, completion times, absorption rates, realistic projections.

You want to look at historical and projected:Rent growthVacancy rateConstruction starts and completionsConstruction/absorption ratioJob growthIncome growthPopulation growthHousehold formationI also like to look at affordability by looking at rent as a percent of income. 

There is still a lot of multifamily being built but it really depends on what your numbers look like and what the market study for the area shows for absorption.

Not to add more work, but it would be interesting to see the listings compared to multi family building permits over the same time period in order to get some more insights into the drivers of absorption rates.  

The appraiser can also tell you how strong the demand has been in the area, and what your absorption rate and future vacancy rates could look like.

Furthermore, they can look at statistics (i.e. list price to sell price %, average days on market, absorption rate) to confirm how hot your target areas are.