At the end of the day we all want money to afford the things we want to accomplish and have in life.Given that no matter who you are you only have so much time in the day.You can leverage people to do more in the same amount of time but the time remains the same.I want to flip this around.A great broker will not only be working with investors but doing deals of their own.If the investor has the know how they can get licensed and do it themselves.Some investors are professionals like lawyers,doctors,cpa's and want to invest but have no time.They need a broker to help them with their goals.There is plenty of business out there for everyone and there are many flavors of investors.If I only have so much time in the day I as a broker want to maximize my return.I can sell a 1 million dollar commercial property and use the same time as selling a 50k property but my returns will be way less.

The areas I listed gives a flavor for the type of neighborhood I'm looking at: a solid B type SFR in a nice neighborhood with good schools. 

There are a lot of people, and each area has its own flavor.  

Milwaukee comes in many different flavors and matching up your investment goals with the neighborhood is key.

My mom has been a teacher in the Lakewood school district for the past 17 years and is very familiar with the neighborhoods and the flavor of the community.

The shutters look bright in the pictures, but they're more subtle in person. 

Zip codes really don't mean anything here because the flavor of an area can change within a few blocks.

Ideally your cost should be less.Note the subtle difference between the 70% rule and what @Arlan Potter posted above.

@Eric Thornton as has been mentioned by @Matt Engle, @Theo Hicks, @Ellie Perlman, @Omar Khan, @Jeff Kehl, and @Henri Meli, there are subtle differences between asset classes in CRE that need to be considered when underwriting a potential deal.  

They are very different types of investments.Commercial RE comes in many flavors as well which further complicates the comparison.I'm starting off into commercial property investment in a small way so that I can get my feet wet.