A linear market is always the best if you don't want to invest in places that have larger boom/bust cycles.

The home is a 2 bedroom/1bath - 816 square foot home.

With regards to the cost to step foot into this loan I’d be paying the 5,000 she has in equity plus the difference in purchase price to sale price ? 

So the value prop is to simply shot gun as many marketing peices as you can afford and then offer 10 to 30 cents on the dollar and wait for takers.. then once you close resell right away.then there are infill lots through out the US in areas that are actually seeing new builds on infill .. infill lots in areas that have zero new construction are basically worthless.. think major rust belt cities were resale values are 100 to 125 a foot or less..

My point is that it's not as linear as everyone makes it out to be.

Several years before we bought a decade old nineteen foot Airstream, parked it on a gravel driveway below our house, plopped down some red lawn chairs and put it on AirBnb.

One year ago I purchased my first rental, house hacking a 4000 square foot duplex.

Someone took the little basket that holds soap and shampoo and the sign on the back of the toilet and placed them waaay in the back of the bathroom cabinet.Someone removed the tiny little LED lights I have on this 8 foot tall fake ficus in the kids bunk room and put in on the deck.

I am considering a 20 foot extension to my cabin - a new master suite with bathroom and fireplace, that would take me to around 2900 feet. 

Most ADUs are ground up and are cost prohibitive. you need to contract dwelling units under 1000 sq ft at $250 per square foot to make the numbers work as a builder in columbus. the cost of an adu and rezoning I'd pass on this one.