My Parents didn't start with one...I don't think I understand what you're saying.To your other point, it's not a matter of trust.

Once they get it, it's a simple matter to convert that to "If you want your money to grow on trees too, then buy an orchard.

If you can answer these kind of questions, it really doesn't matter what metric you use to determine profitability.Also, I personally don't see any point in calculating NPV.  

If you are like Warren Buffett and expect to hold your investments forever, then if we are approaching a cyclical top in your local market won't matter much.  20 years from now when you still own that property you'll be glad you didn't wait until tomorrow to plant that tree.Good luck.

Some people just aren't tech savvy no matter what age.

But no matter how many times it was fixed, it would start leaking again in a year or so.

People are people no matter what they do for a living.

It doesn't matter if the overage/difference was $20,000 that cash belongs to you and only you.

@Greg Gasiorowskilow income areas, you can expect them to beat up the units, no matter what.  

School districts matter when you are trying to sell to a family.