Best thing to do is have an attorney that does commercial help you with due diligence questions and checklist, draw up the contract and handle the closing. 

@Oliver Ham  Find out how much the expenses are and then divide those by the number of people in the home. 

The proximity to NYC is obviously the major draw for most people living within that community and that isn't changing anytime soon.

We kept drawing until 50 people drew the black marbles. 

Add everything up and divide by 360. 

If you use a HML then you will need 10% dp and carrying cost plus enough to pay the contractor to get started until the first draw.

I know that it is common practice to use HML for financing flips, but what are the draw backs of using HML to get favorable pricing on a buy and hold then refinance to traditional financing right after?

If he draws $100k on a HELOC at 5% and lends it to you at 9%, his profit margin is 4%.

Just have to front supplies and closing costs, and we'll get bank draws to pay the contractors labor when work is complete.

Once you have the NOI, divide the NOI by the market cap rate (in today's market conditions, the cap rate will likely land between 6% and 9%, depending on the market you are in.