A temporary market imbalance, combined with cheap borrowing costs (ultra-low interest rates). 

If we got a recession it’s expensive to fly to the Caribbean or Hawaii but it’s still cheap to drove to the Smokey mountains.

Qualifying for ground up construction (GUC) loans without the experience of successful flips or other GUC projects is tough... not impossible, but also notably not cheap.

Examples - owner occupied loans for house hackers, specific market knowledge (ie - friend of mine that ice fishes and bought a short term rental cabin in an ice fishing spot that you and I would never know of), ability to do renovation on your own or cheap, contacts with local companies or organizations that would be a tenant source for mid term rentals, ways to source off market deals, etc.Whatever it is, figure that out and get started.

Then you just moved to a place you moved to not because you want to live there but because it has cheap rentals.

It is not a cheap option, but it is an option.  

I find most of my long term tenants just use cheap runners or area rugs to cover older flooring until they leave.

(or if can you lmk of a cheap wifi carrier/solution that will be used only for hallways and exterior cameras).

I wouldn't cheap out on this part and hire an attorney to help set up a bulletproof partnership. 

Find some land cheap , then resell it for more .