The property is located in Northfield, MA - 2,900 square feet, 4/5 beds, 2 baths, 1.34 acres - quartz counters, marble backsplash, stainless appliances, bamboo floors, 2 decks, whitewash shiplap and completely furnished/staged (I am also a realtor and home stager) - very high end look.

They routinely turned off pool equipment against the lease, they secured the yards irrigation system (we just had the entire front yard done right before they moved in), 3 foot tall weeds in the front yard, and let brown widows infest the back yard. 

I am looking at a possible property to purchase and adding about 400-500 sf of extra living space (den/family room) would really increase the comps for this particular home. I am trying to figure out a ballpark number...

I have 110k and when it's gone I'm at square one again.

I wish I would have investigated more outlets for getting my foot in the real estate door.

It says wet look, but after a week or two of foot traffic it will have a nice sheen to it but won't be super shiny and slick.  

It was a 3/1/2 had gravity fed heat for the first floor & no heat upstairs, it had one 3/4 bathroom (that a 6 foot tall person could not stand up in the shower) and it would need to be significantly remodeled. 

Confirmation Bias --- The tenancy to search for and consider information that confirms one's beliefsPut another way:  If you go looking for Big Foot with the belief he exists......chances are you're going to find evidence he does.

You have to figure out how often the damage is likely to occur and how much the rents would suffer without the finished square feet.

Is that carpet squares or tile?