Your desired cap rate dictates that you will be going after more mom and pop tenant with HAIR as we call it on the deal.The more HAIR a deal has the harder it is to close it and the longer it takes.So it becomes a time/risk reward for a broker.Example on a 1 million dollar property with 8 mom and pop tenants there is a tons of heavy lifting and analyses for a 25k to 30k check for a broker.

This may seem apples/oranges, but Self-Storage and renting houses are surprisingly similar.

Try the FilePlace (http://www.biggerpockets.com/files) for some templates with more detail.Also, as @Jerry W. mentioned, tax benefits are not included in cap rate calculations as the cap rate is a way to compare apples to apples.  

Do all the heavy lifting over the phone or on your website which everyone should have.

If you don't have an Apple device (I have an Android phone), you can listen to them on Stitcher.  

I would try to find out how much deferred maintenance there is beyond the roof (HVAC, etc) and whether the house is going to need a major cosmetic lift after these tenants.

Since Portland lifted that restriction, the number of ADU's has soared to over 600 in 2016- haven't seen 2017 figures and if anyone knows it, please respond. 

Should we get a lawyer to help with the sale, or will a title company do most of the heavy lifting for us?

I spoke with the agent several times and she said the buyer was some big wig at Apple and just wanted to lock down a house and that's why their offer was high.

As a matter of fact they might even be apples and oranges.