Before I commit to a contract I am exploring both options of a conventional refi loan on an existing property i own out right since I have good credit and work a full time job OR...going hard money refi on it.Reason why I'm having a hard time deciding is due to timing. 

@Andrew Mercer its highly unlikely that you will be able to add another unit so before you start anything research with the local code enforcement office to check if there are occupancy permits for the existing 3 units and if a fourth can be added.

But rarely)  This tells me all I need to know - that I was under the wrong impression about what the lender would require regarding using the existing rents to off set the debt.

The interest you save is great and the mortgage balance will accelerate downward faster.So now when that is arranged and recorded - there are a number of things you can do next - refinance - put the seller first in second place - you get cash -- when you are ready to sell you can take some cash, do a wrap on your interest free mortgage and your existing mortgage and charge interest on the money you owe (it don't get no better than that - the yield is off the chart).

I am looking for 80-100k to rehab then refinance in B to C+ neighborhoods (If that exists there).

On this particular deal, there is plenty of parking and there is also a lot of raw land behind the existing structure.

Rehabs are subject to "The Existing Building Code" and the extent of compliance is determined by the percentage of renovation work proposed.

Is there a point when you stop saving money and start paying off existing mortgages faster?

I dont know about Atlanta or GA MSA but there are some banks here in WA these days that go upto 95 or even 100% (according to the flyers I have seen) with a full appraisal and other factors like assets, your financial stmt and other criteria but upto 90% LTV is pretty std I think in most cases for a HELOC on a primary residence and 80%LTV on a cashout on primary residence.If its a rental your only option would be cash out refi @75%LTV as HELOCs on an inv prop are virtually non existent anymore after 2008/2009 market crash but you never know.

64 units X 500 a month = 32,000 X 12 months = 384,000 gross(Take away 60% of expected revenue for vacancy, property management, evictions, expenses, etc.)384,000 X .60 = 230,400384,000 -230,400 = 153,600 expected NOI153,600/2,125,000 = 7.2 cap rateThis is IF there is not existing deferred issues with the property.