If it’s at or near 70% we dig into the full cost model that accounts for financing costs (hard money and GAP), acquisition costs, holding costs and selling costs.

I think you'll see the model continue to evolve in the future, with more "next gen" firms popping up.

I can run and model numbers and am a CPA so comfortable with the finance side of things.

Kudos to you for doing something to create a secondary income stream. there are 5 income streams in RE rentals, possibly six if you do things a certain way.The reality here is your model (buy box) is suffering from too high an entry and too high a cost of capital.

I just used cash to build my first 3 specs no loans at all.. once done and sold then I went to lima got one loan from them.. then went to local bank ( much much cheaper) and got a 3 mil  guidance line and went on to build 30 or so in charleston.. you have to prove the model.. its not like buying a rental where lenders look strongly at your fico  fico is required but not the main consideration like and investor loan and all you need is 20% down or 30% down and a few bucks in reserve that wont fly with spec loans..

I think a return on invested equity analysis outlining a few scenarios with my models would answer your questions. 

It seems the company model has changed a little. 

 - recognize you are combining 2 if the highest effory rent models: student rental and rent by room. 

If there is someone's busines model you aspire to, see what they are doing.

We are going to run it as another bed a breakfast - the same model as the other beach property.