I would in a normal course of a rehab replace cast iron lines on the interior of the home and basement if they are accessible and if I already have a plumber there doing work as those are cheap and easy to replace at that time.

The main reason is labor, and the cost to live around this area is not cheap, so skilled labor demands high wages and benefits. 

Diversified economy, loads of tech money, coastal migrants moving in who still think it's relatively cheap.

That's the easiest, least expensive way to get started and investing in that way in your local market will have a much greater impact on your financial future than buying a cheap house in the midwest- those "cheap" houses tend to be very expensive. 

When I've seen flippers do this, my buyers almost always say, "if they went cheap here, where else did they go cheap."

If you buy them online in bulk they're really cheap and I think it makes a huge difference.Lastly, DoorDash and other apps like it are incredibly useful.

Real estate was cheap in Mississippi, and I could purchase the home with 10% second home loan.

If you have a property manager handling it for you, pass it along to the Tenant at cost of the Workman plus the markup of the property manager, whatever amount that is.Spackle is cheap, but paint can get costly especially if two coats are required. 

I'm not sure of the local job market etc, but maybe someone who wants to save on rent would pay a couple hundred a month to bring in their camper/RV/Travel Trailer to stay in the area for cheap...that's about it I think.  

I also had very long vacancies during unit turnover (2-3 months)I think you will find that there is very little incentive to rent as there are plenty of nice apartment complexes that have amenities that a SFR or Duplex can't offer and the cheap house prices mean someone can buy a house instead of renting.