For example, an asphalt contractor provided us with a today's estimate for resurfacing and a thumb nail guess as to useful life of our roads.  

Great to see my original post resurface from when I was just a beginner.

Roofs need to be replaces, parking lots need to be resurfaced, appliances wear out, etc....This sounds difficult but you should be able to get some help on building your model through your local agents.Good luck

From the photo, it doesn't appear that this condition would be a great candidate for that because of factors like the low height of the window sill, as well as the need to match up with existing sidewalks to be left in place.They make concrete re-surfacers, but your existing slope looks much too great to mess with those.

And I'm wondering what should I estimate as a rehab costs if I needed to do everything - electrical, heating system, drywall, resurfacing floors ... ect.  

I'm in the process of scraping it all off, but it's leaving stains.Ideas on how to resurface on the cheap?

E g rehab on a 1920 built property is likely going to be top tier in expense, but a 1980’s house where you can minimize / eliminate the need to reframe, resurface cabinets instead of replace, etc, etc, this can keep a rehab on < 1500 feet well below $15,000… paint, floors, light fixtures would be typical expense items here, assuming your roof, hvac, hwt etc are all good to go - and they are more likely to be better than the older home.

Had the cast iron tub resurfaced.

A lot of the units need new pool heaters, pumps and AC's and pools need to be resurfaced as they are 15 years old now.

Some of the worst are hardscape resurface, termite treatment (similar for bedbugs), and, slightly less, new roof.