I'm talking about Franklin, Jefferson, or Lincoln counties in cities like Troy (MO), Washington, Warrenton, Arnold, High Ridge, etc. 

You mentioned the Baltimore market and you knowing it very well so you should know what areas and certain pockets of the city are rental areas, flipping areas and some areas that are both.

That X person have Xs units around the country or a city, so how that someone earn money?

I have a house abroad in San Carlos City, Pangasinan. 

The feedback can be brutal when they feature a home, but it's  really good research for City of Atlanta properties.

South Lake Tahoe residents are going to vote on Measure T, November 6th, which would BAN most vacation home rentals in the city.

I have a 15-18 pad park, all city water/sewer and city trash that I can purchase.

Both houses were in the same city and no one we worked with questioned it.

Whereas the 6-plexes are built in 1969 and located in a mid-sized midwestern city with a stable market, but not much growth.

In many places they have been "zoned out" of local cities, meaning the town won't allow any more to be built (unless a replacing existing).