I am sure AirDNA has more info for their paid subscription, but this will give you some kind of idea.

The seller of the property built them back in the 90's and paid in cash for them. 

On one side, it seems to involve a decent amount of expenses/high cut out of the agents profit.

Paid cash, so no mortgage. 

My biggest expense has always been HVAC systems.

Outskirt towns are less expensive but may see less appreciation if any at all.

It’s too expensive!

Look at all the KPIs like occupancy and rate.Do you have other expenses that go up, like utilities, yard care, internet on MTR?   

If a commercial property such as 9+ residential units (such as an apartment building) or not residential, the below doesn't apply. 9+ units typically take extra expenses into consideration such as management fees, utilities, etc. 

But the reality may be that the tenant hasn't paid in two months, or pays 20 days late every month, or their dog is destroying the carpet, etc.There are literally hundreds of threads explaining the dangers of buying a property with existing renters.