First Flip Deal Need Help Finding a Comfortable ARV

[Michael Lee]

Hello, All 

I found a great potential deal in West Palm Beach that I am looking to renovate as my first full fledged flip. However the property has been pretty difficult to comp with only two slightly comparable properties to go on.  Here are the specs 3/2 @ 3,214 CBS Home sitting on an Acre lot in a quiet area. 

Now the problem I am facing here is that it's classified as a 3/2 this area is about 1,595 sqft and here is where it gets interesting there is also additional 1,618 sqft of space that includes an additional kitchen and 2BR and 1BA with it's own separate entrance, the county website includes the additional space as a semi finished space but not the bedrooms and bathroom so it's basically seen as a large space 

The only similar comps are a 3/2 @ 1,530 sqft which sold for $305,000 on an acre lot and a 5BR/4BA with a pool @ 3,170 sqft which sold for $490,000 where I am getting confused is should I assume the property as 3/2 since the county only sees it as a 3/2 or a 5BR/3BA because thats what's there.

I do have a few days to decide but I am looking to either bring in a partner or a hard money lender on this deal so if anyone has any knowledge on how to attack this one I would greatly appreciate it