Below are links that I feel may be helpful.
https://www.oregon.gov/dpsst/PI/Pages/Private_Investigator_Business_Listing.aspx
Most states requiring a P.I. license will have a list of licensed investigators active in the state. Here is a link to the Licensed Private Investigators in Oregon:
I like to recommend that if people are limited on funds, that they do as much research as they are comfortable with on there own. It is important to know what laws govern the area your in. In Oregon you can access the statutes here: