I'm currently budgeting $1,500 for that alone (including the demo of existing kitchen).- Counter tops: I have been quoted, in total, for design, material and install, just under $1,600 for white quartz counter tops which seems like a fair price to me.

. - I estimated around $5,000 for demo.

There will be a decent amount of demo for the sq. footage since I will be breaking through the bedroom wall and closet.

@Helen Yang I have not raised rent yet but is their renewal coming up?

I was thinking to somehow acquire the property for next to nothing from the current owners who will likely get an insurance payout, use my connections with my old company and suppliers along with BP and other resources to demo (if not complete already) and rebuild with a combination of donated materials, money, time, and whatever paid services may be required. 

Most inspectors will want to peek behind the walls and you may have to pull all the drywall so they can see all the framing, plumbing, and electrical.Definitely adjust your numbers on the deal ignoring that square footage and subtract any costs that may be associated with demo or corrections from the purchase price.It might be worth just getting a preliminary inspection done by the city just to give you an idea of what it will take to get it approved.

- Labor, demo, foundation, rough materials etc. 260k- Labor, finished materials 50kLooking at ADU options prefab or stick build, we could add 500 to 700sqft for like 200k to 250k saving at least 70k in investment.

When I got there, 3 houses were flooded and I had to stay for another two weeks demoing everything myself and trying to find an available contractor.

On the other hand, a fill demo and drywall job may also put this outside the profitability range.I’d love to make this home beautiful again, but I think I may need a partner, possibly a contractor, to help guide in repairs. 

I would say managing the construction of a 3500 sqft house through demo of an existing structure, new site work, at carrying the project all the way through to the end would be quite an undertaking - especially with minimal construction experience.