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).

@Amy Ranae if you don't know about the City of Mpls small developers class check it out. 

Well I did get a new job as a Project Manager for an Electrical Contractor in the Twin Cities on January, 7 2019, and that layoff was a wake up call. 

I find that my rentals in the far outlying suburbs all tend to get tenants from Zillow, but my stuff close in close to the city or in the city tend to be Craigslist.I dont like that a lot of the listings, whether for properties or for rent on Zillow tend to be outdated...so it looks like there are more rentals available than there really are.

And in the cities I know nothing can be bought in this price range.

If you're looking for deals in the city, then I'd 2nd what @John Warren said. 

New York vs.