They get approached by bankers, wholesalers and brokers looking to unload numerous foreclosed or brokered properties quickly.

I know how much outlets cost, switches, light fixtures, tile, paint, lumber, drywall and labor for all of these things.

The owner was unloading a good amount of his portfolio to invest in commercial retail buildings.

Identify what you hate doing, and unload those tasks to someone who loves doing them.   

Then, install a decorative medallion on the visible end of the lumber.  

It's the bare minimum and that's using my credit accounts (not accounted for in above 15%) at the lumber yard that will buy me 30 days for the framing, roofing and siding.The numbers you gave above I wouldn't bet success........BUT I'm pulling for you!!

They have had them for a while and figure the market nationally is spicy right now and its time to unload.

They don't care about the cashflow, they're betting that Google (Silicon Valley), or Hollywood (SoCal), or the Bay Area housing crisis, are going to yield some combination of high demand and incomes, or low housing supply/production, or both, and thus appreciation per year greater than the short term negative cashflow, averaged out over a decade or two, at which point they unload it all and retire to the Bahamas (or whatever).In NYC perhaps the example would be a luxury condo a block from Wall Street.

I have low balled a few whole salers that initially balked at my price only to have then crawling back 2 weeks later looking to unload the deal.

If you are worried about the 1/2, tell them you will either pay 1/2 upon delivery or set up an account at the lumber yard to by it with.