Non-performing notes are on the OPPOSITE side of the Active - Passive spectrum requiring several people to assist you, costs to evict or perfect, and servicing of owner occupied homes, many times, with required disclosures.  

Let me know if I can help run any numbers or give you any advice about properties on the south end of your spectrum.

Is it a function of units or time or variety or spectrum of industry exposure?

The top end of the spectrum $1700-1800 there are certain features you need in the house.  

I recommend checking out the podcasts, they're a great way to get exposure to the entire REI spectrum.  

Very interesting @Jon Holdman, most people never talk about that end of the spectrum.

@Jason CarterIf you do a search on BP you'll find a ton of people who advocate both sides of this spectrum.  

There are many debates on BP about the Bay Area, and when going into any purchase the ultimate test is deciding if it fits your long-term plan.The San Jose market and Oakland have the spectrum of duplexes.

Palm Beach County is a big spectrum of areas, ranging from the low low to the super high.

But affordability really be stretched across the spectrum, with the Fed left to do a lot less than they could in the past..