The first deal using a lot of leverage is great as it allows you get your foot in the door!

You could also call a couple of contractors on the phone and get rough sqft pricing from them for roofing, siding,  painting etc. like how much the averages costs are per square (100 square feet) and square foot .

OpenAI, a leader in artificial intelligence, has leased the entire 315,000-square-foot building at 550 Terry A Francois Blvd. in San Francisco’s Mission Bay neighborhood.

Also assumptions on cost if you pick and they buy A $10 a square foot flooring when they budgeted $5, big difference.

I had been insuring at $350-$400 a square foot value the last year or two

In 2020, I built under $200 a foot with long-term rates in the 3's to get 40% ROI.

@Dalton Foote I think this is the key point. 

Does it have 36" windows egress, 7 foot ceilings, egress doors, HVAC, and closet door? 

The 315,000-square-foot space in Mission Bay adds to OpenAI’s nearly 1 million square feet of leased space across the city, including properties subleased from Uber last year.As one of the largest AI firms in the world, OpenAI’s expansion is helping revitalize San Francisco’s struggling office market.

I bet you did not have that one in your bingo card...