sellers dictate the terms not the agents..  

thanks I about went crossed eyed trying to find the MSA s i deal in  LOL.I see this as highly regional.. and there is no question in the mid west markets were you have areas of declining value and have had for many years that exsiting is far cheaper than new builds.. in some markets this keeps new construction either non existant or only for those building their own custom home.but in many cities the homes that are so far below new construction pricing the areas are tough rough and schools not to swift.. and that dictates pricing not the replacement value .. but just the fact that a builder is not going to risk building in some neighborhoods were the new home buyer simply would never consider becasue of these factors.So all cities have there hoods or less desirable areas.. 

There is very little multifamily inventory so you may find the inventory dictates the location, not the other way around.

They almost need to be viewed as a special use property.The infrastructure supporting the location often dictate whether a parcel/building is fit to use as a Data center.Huge learning curve in this niche product type.

Your location and price point will definitely help dictate which strategy makes the most sense - I will say that in Seattle proper our experience has been that SFH's with a MIL or ADU actually have better cashflow and appreciation.