We've tried to make it painless for him by going to him to sign things, but he is not thinking and acting rationally.

I will not give you the answer - that's for you to rationalize.

The core of all sales of this nature is to appeal to your emotional side so that you ignore your rational side and make a rash decision like sign up for some online coaching course.  

I need some sense talked into me to help me rationalize this decision.

I am a big believer in the fact that people are rational self-maximizers in virtually all endeavors.

You start trying to rationalize marginal tenants. 

When put in those terms, it is clear why an exit strategy should always precede an investment.I've heard many former colleagues (prior to my retirement) attempt to justify and rationalize poor decisions in their minds.  

There may be a particularly pernicious debtor who has gone "Ruby Ridge" and unable to deal with their problems rationally and detach from a property.Ultimately, time and Mother Nature will solve any problem that is not resolved by persuasion, courts or non-judicial sale.

Your PM will typically want a larger percentage to accommodate for this.From our experience, I would expect PMs make more money taking a lower percentage on a higher class building simply because the rents are higher and the management effort is less.b) A quality candidate for super will require "incentive" to live in a lower class building and/or rougher neighbourhood.I'm sure others have additional rational, but this is out experience.You have already collected several of the other reasons why the PM fee on a larger building: 1) There is an on-site super and, if large enough, perhaps a separate maintenance person; 2) The economy of scale:  managing 100 units in one location is less effort than 100 SFRs. 

What rational investor would make anything other than a lowball offer on a 90-year-old property without an inspection?