Phoenix, AZ ADU/Casita and "Rent Per Room" Rent Help

[Caymian Gordon]

Hi Everyone! 

I am looking at purchasing a property in the Phoenix, AZ area that has a fully build Casita/ADU on the property.

There are also extra bedrooms I am looking to fill on a "Per Room" Basis instead of having a blanket lease and allowing the tenants to split the costs amongst themselves.

How would I best go about finding rent comps for the individual rooms I look to rent as well as the Casita/ADU located on the property?

Any help is much appreciated.

Thanks in advance!