I have heard of investors getting properties for really cheap in Dallas, But every time I look on Zillow or Redfin I see no properties close to that price.

Locust street runs into the campus but even "bad" streets in Valpo are not cheap.

The underlying notion that every "cheap" house is a dump in the middle of a war zone is far from the truth.

Midtown, Corktown area.In other areas of Detroit, houses are cheap, so some people are trying to re-purpose these properties. 

And electricity isn’t cheap here either.

I have close to 22k in the account and have started to invest in cheap duplexes (ranging from 50-70k, so this amount would allow to put down 20% on a couple of these. 

It's based on the best (cheap) software that I've found Cash Flow Analyzer.

If the area is really cheap, its probably not a good area.

I’m saving for next downpayment and trying to decide if I want to eliminate the auto debt (and essentially “buy” an extra $1100/mo of cash flow to save/invest), or if I should let those low interest notes hang around (after all, 2.5-2.75% seems like cheap money).

I'm not sure what you are considering low cost, but if you are considering buying cheap properties in low end neighborhoods, then that is not a good strategy.