Agree with other comments here. A two-year vacant house in unfinished condition, is going to be a long inspection. Probably zero security over that time. No atmospheric conditioning over that time. Amazing how much deterioration can happen to an uncared-for building in two years.
My basic model is $350 + .05c per sq ft. Homes of that size I do add a bit more on to.
I performed a similar inspection, but the time frame was approximately 6 months. In that short time, water damage was significant. Rusted fasteners, mold, and most of the OSB subfloor and engineered i-joists had deteriorated. That was basically my narrative, lol. Structural engineer time.
You reminded me of an inspection on a HUD home that I did in the foreclosure years. The house had been vacated in December. The power company turned off the electricity, but since water bills can be leaned here, the city left the water on. In January, it froze and then flooded the house. I am there in July. Every square foot of the house had mold. The humidity had swollen the composite cabinetry and the water soaked cabinets in the kitchen had fallen off of the walls.
I asked the client who was a fix-n-flip investor why I was there. He said that his realtor had told him that I was an idea guy who could give him some out-of-the-box suggestions on rehabbing the house. So that was what I did, cuz the inspection report was basically “gut and re-do.”