So our PITI on the home is $4,020/mo.Keep as rental- Market comps suggest a wide rental range - $3,800-$5,000+.

The rental market in the mid to higher price range is a bit lacking so having a rental in that range should go quickly.

I just randomly picked Cincinnati and looked for duplexes in your price range.

However, my take on this is they did not do sufficient due diligence on many fronts, including city government challenges, operating challenges, infrastructure challenges and marketing challenges. 

I purchased both STR houses in the low-600s range.

Prop tax ranges from 2.5% in fate to 2.16% in Rockwall city. 2.16% is some of the lowest you'll find in DFW. 

Rates will be a little higher (5%/6% range) but the cool thing is that you can often find these on 30 year fixed terms unlike the short term balloons the local bank would offer. 

I met with him the next day and made an offer in the range of $40,000 to $50,000.

Once you have sufficiently built up your leverage, you can make a pitch  to someone with cash to and they may bite.  

Keep as rental: Rent comps range from $3,800–$5,000+.