Help Determining Offer for 4Plex! Comps Lower than Asking!

[Raden Mantuano]

Hey thanks in Advanced for anyone that can help us out here..

So we are talking directly to a seller who is open to selling her 4plex in Ohio at a price of $150k.. Section 8 approved.

2 units are occupied

1 unit is vacant but rent ready (However, out dated) 

1 unit needs a total rent ready gutted rehab (Images provided) 

Current Cap Rate based on NOI given ($21k) and some change with a purchase price asking is around 14%

Brings the FMV at around what she is asking at $150k..

However, based on the given that a 4plex is still considered a "residential property", the income approach doesn't matter? I'm assuming the value will be based on comps. Since I have access to title I'm able to do the same comp research a realtor would. I'm seeing comparable sales, but having a hard time determining ARV, the highest comparable i see is a $162k for a 4 plex... but cant tell what condition of the property was only thing I see, is that it was a tad bit bigger in sq ft and a bit newer.. in this case how would I determine what I'm suppose to offer? we have a scheduled contractor walk through tomorrow and that will help give us the estimate on what needs to be done, from just the pics, we are looking at maybe $30k + on this..

Because seller only wants cash, We are considering entering this deal using the BRRRR strategy, using a Hard money lender. So based on that, i'm assuming we need to enter the deal at 70% below the ARV (Which im having a hard time determining.)

Note: Based on title this 4plex is considered "Commercial" screenshot provided. This is where im confused as to what the heck this property would appraise for or how it'd appraise for so we can make our offer that makes sense.. thanks again guys..