But due to some unexpected family stuff, they were forced to hold off on their plan and push back the move to Las Vegas by about 2 years.Now, to avoid paying for two houses at once, they're planning to rent out the Las Vegas house until the family issue is sorted out in California.

She then told me that was an accident or a mistake so...  

I’d still build up some savings so you aren’t going into it dry if you have some unexpected repairs though. 

If you are happy with your "Estimate" and still OK with the "High" estimate then its probably a good deal because likely everything won't go to a worst case scenario and also if you apply project management principles you can adjust the time or scope of work to try to compensate for many unexpected things that could come up.

It's not by accident, that happens on purpose.

Like all insurance, pay now through the nose, or pay after the accident out the other end!

That doesn't leave much for unexpected issues.

It's (how bad do they want it).When my father was killed in a car accident when I was just 16 years old my mom and I were left with next to nothing except an old house that was falling apart and enough proceeds to survive maybe a year on.I outworked physically many of the people out there having a fruit market job across the street from my subdivision when I was 14 years old.

That's not just the risk of vacancy, that's the risk of not knowing how to find and vet a property (not all distressed props are created equal and its crucial to know what to look for in terms of 'good bones'); it also includes the risk during rehab - if something unexpected comes up or you need to take time away for any reason and work needs to pause, that's additional time that you're paying the mortgage with no income.

How about an accident in the common area-parking caused by a tenant with previous DUI?