This is probably different for multifamily where renting it out is their only option.

the way section 8 works is different in every county across the US and I have been diving into the matter myself for an 8 unit I am considering putting into section 8 in St petersburg Florida.. but from my understanding you would ask whatever rent you are hoping to recieve and the tenant will tell you what their TTP or total tenant payment is and the county is responsible for covering the remainder of the lease as long as it is beneath their FMR fair market rent.

I also look at capital appreciation, tax savings, cash flow and cash flow appreciation.Where you invest, investment support structure for each property, and additional factors important to your individual decisions all make a difference as well. 

Depending on how close to Lackland also will make a difference.

Is this $20k over on a $200k property (10%) or a $400k property (5%), that too makes a difference.

(audience of commercial brokers)  One agent asks another "I'm thinking about going to work for a different broker, how many work at your brokerage?

As I understand, theres a big difference.

I've been reading every book on here I can find, but they all seem to be from a few years ago when the economy was much different.

Every lender works the draw process different. 

Sometimes different challenges come with that (utility availability).