BUT we had to buy one for one of our aging parents.

I see I made a major deficiency in purchasing my current property with the age of the key items, e.g. gas furnaces, water heaters, washer/dryers, refrigerators, stoves, plumbing, electrical, etc.

As Joe mentioned above your age is going to be a huge factor to creating generational wealth as your investments will have more time to compound. 

So much depends on age and condition of the building.  

You may not want to have that capital trapped in that plan until such time as you change jobs or reach age 59 1/2.

My tenant's other son, age 32.

Also probably ~8% of rents for repairs capex depending on the age of the property and about 5% for vacancy depending on the area. 

Office vacancy for San Diego as a whole is around 9%, but I would be concerned about the age of the asset (probably some deferred maintenance to consider even though it's well maintained) and that its off the beaten path in Poway. 

I've known him for ages, and he is not interested in the real estate.

;<))The price is completely dependent on income and adjust for age or lack of maintenance and deferred CAPEX.