SO, is there a formula to calculate current equity value or resale value vs income, I should look at. 

You should go through the exercise of building your own and understanding every number and how the formulas work. 

I posted about this experience recently: https://www.biggerpockets.com/blogs/8160/71180-we-...With a master metered property, you have a few options: (1) you become responsible for the water bill and include a flat fee in the rent (2) sub-meter the property so each unit is on their own meter, making the tenant responsible (typically VERY expensive) or (3) implement Ratio Utility Billing System (RUBS), this is where you are still responsible fo the water bill but through a formula and spreadsheet bill back the tenants their fair share.

@Mark Lange I suggest learning the definition, purpose, and application of the formulas below.

From the formula, we know that cap rate starts with NOI (i.e. revenues minus all operating expenses).

I know this deal is not so good as the CACROI is very low but my main interest is if my numbers/formulas are correct.

If you do want to dive into this, I would recommend taking Brian Page's AirBnb Formula class.

This is my formula;  ARV x 70% - Rehab estimate - Holding costs - Closing costs = Maximum Allowable Offer (MAO) or.

Are you making these offers on properties that fit the formula, or are you trying to force the formula onto properties that will not work?

In other words, before going through the whole refinance song and dance, can I just capitalize the increase in NOI by the same rate used by the original appraiser to get a pretty close estimate of value OR are there other factors that could dictate the cap used by the refinance appraisal?