What I usually do is take the most recent 3-5 properties and do an average price per square foot and then your subject property multiply the square footage by your average price per square foot - this should get you close to a comp price.  

The building has a Gross Multiplier of 18.   

Now, if we multiply this by 10..... we get the Manhattan to Brooklyn scenario in real terms.Here is the exact statement above multiplied by 10:I fully believe that couples who own a $10 Million apt in an expensive neighborhood would move to a $1.75 Million home that's only 30 minutes away.

My rule of thumb is to count the number of bedrooms in a house and multiply it by $200, that's how much I charge a week. 

Then you need to use the 2016 tax millage rates to multiply out the valuations.This will give you the tax amounts.

Multiply that by 3% basically gives me a discount of $3500 on the house.  

I like a gross rent multiplier (GRM) of 8 or less.

RE Taxes have local area multipliers that are applied to the assessed value to determine the annual re tax.

I've also heard that mortgage company will look at what market rents are and take a view on that, rather than literally multiplying rent x cap rate to arrive at a valuation.

Multiply that by OPM and you have yourself a winning formula.