@Michael Newman,I use these sources:current T12 & rent roll (if available)comparable rents from broker's OM packagecomparable rents from neighboring properties (MLS, rentometer.com, umovefree.com, calling to the property)expenses provided by management companies that have similar properties under managementexpenses (ranges) from NAA survey - usually outdated but give a 10000 ft picture and helps establishing some baselines.

One of the awesome benefits of commercial real estate compared to residential.  

In prior purchase, I used a PNC personal loan and I had some reserve thus, I used that PNC 8k loan and my 5k and made my duplex purchase.

For instance you can learn the market and know where it is going, appreciation values, comparables, and so much more.

Lucie and Indian River Counties of Florida  Mostly looking in Fort Pierce but also Port St Lucie & Vero Beach  I welcome local contacts to compare notes  

If I was to purchase a multifamily investment, for example a 6-unit property, and turned two of the units into vacation or short term corporate rentals that increased NOI when compared to traditional rental income with lower NOI, how would lenders look into this in terms of a value add to the property?  

You could start by looking at nearby comparable properties to see if they allocate any of these costs to the tenant via RUBS or something else. 

Prior to inspection, your response is that you have never tested it so unknown if lead is present.

We are getting started with Wholesaling and working with FSBO homes.My question is "How do we get accurate comparables if no realtor is involved?"

Outside of my primary residence, I do not have any prior REI experience.