For example, CoC may tell you something about your year 1 cash flow, but will tell you nothing about appreciation (forced and/or market), rent growth, CapEx, quality/volatility of cash flow, mortgage pay down, tax benefits, management headaches, or the risk you will be taking on to achieve that CoC ... all of these things mentioned and more are critical points to be considered that CoC alone tells you nothing about. 

This sounds like a triple net lease opportunity, so you would not have to pay taxes, insurance and maintenance on the property if you have a quality tenant.2.

I'm just getting started and I'm looking for referrals for a quality real estate minded CPA and lawyer.

Let's say you have no 4-plexes comps in the area but there are duplex comps:1) 2000SF duplex #1 sold for $200,000 -> unit size: $1000SF2) 4000SF duplex #2 sold for $300,000-> unit size: $2000SF3) 1200SF duplex #3 sold for $150,000-> unit size: $600SFlet's assume to make things easier they are all the same grade of quality and they are all leased to tenants at market values.Duplex #1 sold for $100 per SF and $100K per unitDuplex #2 sold for $75 per SF and $150K per unitDuplex #3 sold for $125 per SF and $75K per unitNow you have numbers you can compare to your 4plex.

In an appreciating market like we have this might work for the right person as long as they do quality work and want to be the end buyer.

In many lower quality areas the prices have not increased much.  

It is still very important to make sure you have a quality contract and have hired someone capable of finishing the job.  

Nikolas Ferreira how do you figure who is the builder of a house , and where do you find information about the quality of each builder?

Chicago, Indianapolis, Kansas City.Based on reasons I list out in here (quality of market + quality of turnkey provider)-https://www.biggerpockets.com/renewsblog/2015/12/2...Those 3 are my favorites right now.

If not have them give formal notice now allowing you 3 full months to find good quality replacements that are able and willing to pay market rent.