In general, investigation expenses and participation comes into effect when you close.

Anyhow, there was some useful general information that let me wanting to investigate further.

Most Realtors use the standard contract and probably aren't too keen on deviating from that one.I know in my state, the standard purchase contact allows for an inspection period (17 days by default but it could be changed to whatever) that allows the buyer to "complete all buyer investigations; approve all disclosures, reports and other applicable information which buyer receives from seller; and approve all other matters affecting the property".

I have been thinking and investigating about AirBNB arbitrage.

Depending on his disability you can hire an investigator to follow him to get evidence its not real.

And if any part of your desired journey involves selling an investment property then investigate if the tax deferral of a 1031 exchange is worth doing in that particular instance. 

When we went to investigate further we found that this small area had a great view and so we decided to build a tiny house there.

Two weeks later after finding nothing I went back to my realtor and had her investigate that same property again.

What's significant about a commission complaint is that the commission investigates and if they find probable cause for bad behavior on the realtor's part, the realtor can be fined and you can be compensated with damages, all of this without having to go through civil litigation.

Do your homework, and investigate and make sure it's legit!