It seems like I'm always a day late to most parties and just don't want to jump into a new career/venture only to find in the next 10 years, all my investments are diluted due to the increase in inventory. 

I have my eye on a great deal, but the seller isn't willing to wait for conventional lending. 

My dilemmaI am good with conventional financing on the $30,000 as the zestimate is $44,000. 

Instead of using a conventional mortgage. 

How long until a conventional lender will loan against the project and allow me to continue with phases 2 and 3?

All conventional loans will top out at 80% of the appraised value.

If conventional financing or cash it might be OK as a primary residence but it isn't the deal of the century or anything.

@Allen Li  for 2-4 units you don't need local lender, you can use any conventional loan broker.

Ideally, I would like to buy a duplex or a SFH 3/2 20% down using a conventional loan.

An FHA allows us some flexibility which is nice because we can lay down a lower down payment and keep some of the money in reserve in case of emergency, but the appreciation of a home in Detroit with a conventional loan is much higher.One other option that we have explored is buying a rental for the purposes of Airbnb in a different state.